How I Solved ‘Operating System Not Found’ Error

Staring at the “Operating System Not Found” error on your Windows boot screen? That gut-punch moment when your PC refuses to start can halt everything. If you’re dealing with corrupted boot files or misconfigured settings, this step-by-step guide has you covered. Try these 6 steps, starting with BIOS adjustments and ending with Command Prompt fixes through Diskpart, to check for problems, fix them, and start your operating system again soon without deleting files or wasting time.

1. Diagnose the Initial Symptoms

When your Windows machine flashes the ‘Operating System Not Found’ message right after powering on, it’s time to note details like any beeps or LED patterns indicating the issue.

To fix the problem, restart your computer and press Ctrl+Alt+Del to access recovery options. Or, when starting up, press Shift+F10 to open Command Prompt, as described in Microsoft support documents.

Common symptoms include no boot on HP laptops, often due to missing HDD partitions per HP community forums.

To differentiate hardware (e.g., failing drive shown by clicking beeps on Dell systems) from software issues (like corrupted boot files), run the command ‘bootrec /fixmbr’ in recovery mode.

HP support threads highlight checking BIOS for drive detection; if undetected, it’s likely hardware failure needing replacement, per a 2022 HP troubleshooting guide.

2. Access BIOS Settings Safely

Imagine pressing the wrong key and risking a system lockup-accessing BIOS on an HP notebook starts with powering off completely before hitting F10 during startup.

Like Alden4 from the HP Support Community, who faced boot failures after a faulty update, many users worry about accessing settings safely without falling for scam ‘diagnostic tools’ peddled on shady forums.

Turn off your notebook completely to avoid risks. Do not use sleep mode.

1. Press the power button, then immediately tap F10 repeatedly until the BIOS Setup Utility appears; ignore F2 or Esc to prevent lockups.
2. Once inside, use the arrow keys to go to the ‘System Configuration’ tab, choose ‘Boot Options,’ and change the priorities (for example, turn on Legacy Support if you need it).
3. Save changes with F10, exit, and reboot.

This resets errors without third-party software, restoring normal operation in under 5 minutes.

3. Adjust Boot Order Priorities

Prioritizing your internal hard drive over USB or DVD in BIOS can fix boot issues faster than chasing software glitches.

For Windows 11 upgrades, internal drives offer faster boot times and reliability, avoiding USB/DVD’s potential connection errors, but externals are essential for installation media.

Weigh pros:

• Internal drives reduce latency (per HP Support docs)
• external devices enable clean installs but risk data corruption if improperly ejected.

Compare boot modes-UEFI (secure, GPT-compatible for modern hardware) vs. Legacy (BIOS, MBR for older systems)-via HP’s BIOS guide: UEFI suits Windows 11’s TPM requirements, while Legacy may cause compatibility issues.

To adjust boot order:

1. Restart and press F10 (HP) to enter BIOS.
2. Navigate to ‘Boot Options.’
3. Set internal drive first, save/exit.

Community forums like Reddit’s r/techsupport recommend disabling Secure Boot for multi-device setups to resolve conflicts, as seen in common Windows upgrade threads.

4. Verify Hardware Connections

Loose cables inside your laptop might be the hidden culprit behind the boot error, especially on older HP models.

To troubleshoot, power off and unplug your device, then carefully open the back panel-always use an anti-static wrist strap to avoid ESD damage, as warned by HP’s community forums.

1. Start with a visual inspection: reseat the RAM modules by gently pressing them into their slots, ensuring no debris obstructs them.
2. Next, check the SATA cable connecting the hard drive; a loose connection can prevent booting and risk data corruption-HP advises verifying it’s firmly attached without forcing it.
3. If issues persist, consult a professional to prevent data loss.

This method resolves up to 40% of boot failures per HP support data.

5. Run Startup Repair Tools

Have you tried starting a computer from a Windows USB and run into problems? Startup repair scans for boot file issues automatically.

1. If it fails, create fresh installation media on another PC using Microsoft’s Media Creation Tool-download from microsoft.com and select the correct edition (Home/Pro) for Windows 10/11 compatibility.
2. Boot from the USB drive first. Select the language, like the en-US code for English. When the setup screen appears, press Shift+F10 to open the Command Prompt.
3. Run ‘bootrec /fixmbr’, ‘bootrec /fixboot’, and ‘bootrec /rebuildbcd’ sequentially to repair boot records.
4. For transitions between Windows 10 and 11, verify UEFI mode in BIOS matches your media.
5. This method, per HP support docs, resolves 80% of boot loops in under 30 minutes-always back up data first.

6. Reinstall Operating System if Needed

If repairs fail, wiping and reinstalling Windows from DVD or USB often revives a stubborn laptop, but back up data first.

For boot issues post-wipe, a real-world fix comes from an HP Support Community thread dated September 23, 2023, where user Alden4 resolved a non-booting HP laptop.

1. Back up your data first. Boot your computer using the Windows installation media. Open Command Prompt. Run Diskpart to wipe the drive. Type select disk 0, then clean.
2. Then, create partitions: create partition primary size=100, format quick fs=ntfs label=”System assign letter=S; create partition primary, format quick fs=ntfs label=”Windows assign letter=C; active.
3. Rebuild boot files with bcdboot C:\Windows /s S: /f UEFI (or BIOS).
4. If errors persist, rename corrupted BCD: ren S:\Boot\BCD BCD.old, then rerun bcdboot.

Alden4’s solution earned kudos and was accepted, restoring full functionality per HP guidelines.

What Causes the ‘Operating System Not Found’ Error?

This frustrating error pops up when the system can’t locate boot files, often stemming from overlooked hardware or config slips on Windows devices.

Key triggers include a missing active partition or corrupted Boot Configuration Data (BCD), as outlined in Microsoft’s Windows boot troubleshooting documentation (support.microsoft.com). These often arise from improper disk partitioning during installations or failed updates.

To locate and repair the problem, open Command Prompt in the Windows Recovery Environment.

Do this by pressing and holding the Shift key as you restart your PC. Then:

1. Run ‘diskpart’ to enter DiskPart tool;
2. type ‘list disk’ and ‘list partition’ to inspect setup;
3. select the system partition with ‘select partition X’ and set it active via ‘active’.
4. For BCD corruption, execute ‘bootrec /rebuildbcd’.

HP forums frequently cite BIOS Secure Boot toggles as culprits, recommending firmware updates from hp.com/support for laptops.

Identify Common Hardware Failures

A failing hard drive tops the list of culprits, where sectors go bad and prevent OS detection during boot.

To diagnose quickly, start with low-effort checks.

1. Listen for unusual clicking or grinding noises from the drive, a common sign of mechanical failure as noted in HP community forums and Seagate’s troubleshooting guides.
2. If external drives are connected, disconnect them immediately to rule out conflicts-simple swaps often resolve boot issues per Microsoft support docs.
3. Next, update your BIOS via HP’s official tool (download from support.hp.com), which takes under 10 minutes and fixes firmware glitches in 40% of reported cases according to HP’s 2023 reliability study.
4. If symptoms persist, run Dell’s built-in diagnostics (F12 at boot) for a free sector scan.

Explore Software Corruption Issues

What happens when a Windows update mangles your boot configuration? Files in the system drive’s EFI folder get scrambled.

Don’t assume hardware failure-many users mistake this for a dead drive, but it’s often fixable via software. The EFI partition holds bootloaders like bootmgfw.efi, which updates can corrupt without touching hardware.

To recover, boot from Windows installation media (create via Microsoft’s Media Creation Tool).

In Command Prompt, run these steps:

1. First, run the commands bootrec /fixmbr and bootrec /fixboot. These fix the master boot record.
2. then ‘bcdboot C:\Windows /s C: /f UEFI’ to rebuild the BCD store.

HP support forums (e.g., threads dated 09-29-2023) confirm this resolves 80% of post-update boot issues, restoring access in 30-60 minutes per user reports from Microsoft Docs.

Review Boot Configuration Problems

Boot configs go awry if the partition isn’t marked active or BCD store is mispointed, common after dual-boot attempts.

To fix this, open Command Prompt in the Windows Recovery Environment. You can do that by pressing and holding the Shift key as you restart.

First, use diskpart:

1. type ‘diskpart’
2. ‘list disk’
3. ‘select disk 0’
4. ‘list volume’
5. ‘select volume 1’ (your system partition)
6. and ‘active’ to mark it bootable.

For BCD issues, run

1. ‘bootrec /fixmbr’
2. ‘bootrec /fixboot’
3. ‘bootrec /rebuildbcd’

to rebuild the store.

For UEFI setups, use GPT partitioning with a GUID. Convert with Microsoft’s MBR2GPT tool, available from docs.microsoft.com.

Check HP forums (e.g., h30434.www3.hp.com) for dual-boot GUID vs. MBR guides.

Test with ‘bcdedit /enum’ to verify paths.

These steps resolve 80% of cases per Microsoft support data.

How Can You Avoid This Error Next Time?

Stopping this boot nightmare before it starts involves simple habits that safeguard your Windows setup on laptops.

1. Begin with regular backups using external drives like the Seagate Backup Plus (1TB, $60), connecting via USB and scheduling weekly full-system images with Windows Backup or Macrium Reflect (free tier).
2. Next, update drivers via HP Support Assistant for HP laptops, which scans and installs the latest versions automatically, or use Device Manager for manual checks on Windows 10/11.
3. Then, perform firmware checks, including BIOS updates from the manufacturer’s site-HP users can download from support.hp.com, following on-screen prompts during a powered-off state.
4. Monitor with tools like HWMonitor (free) to track temperatures and errors, preventing issues as noted in Microsoft Community FAQs where overheating caused 40% of boot failures.

If these steps don’t resolve lingering boot problems, explore my step-by-step fix for laptops that take forever to boot to get back up and running quickly.

Implement Regular Backup Strategies

Regular backups aren’t just insurance-they’re your lifeline if the OS vanishes, using USB or cloud as per HP advice.

Take Sarah from a Reddit forum thread last year: she clicked a phishing link promising a free Windows upgrade, only to lose her entire OS and irreplaceable family photos.

Scammers then demanded ransom for ‘recovery help,’ leaving her in shambles.

To avoid this, always image your system to an external USB drive before upgrades-using Windows’ built-in Backup and Restore tool (search ‘Create a system image’ in Control Panel).

HP recommends full backups monthly, with incremental ones weekly via tools like Acronis True Image (free trial available).

This protected my data during a bad update. Set a calendar reminder to check restores every three months to stay secure.

Maintain Updated Drivers and Firmware

Outdated drivers can trigger boot fails during Windows 11 shifts, but HP’s auto-update tool keeps things smooth.

HP Support Assistant automates driver checks and installs, scanning for Windows 11 compatibility issues like TPM 2.0 mismatches without user intervention-ideal for beginners to avoid boot loops.

On the other hand, updates through Device Manager let you handle things exactly, like getting Intel graphics drivers from HP’s website, but you must check versions to avoid problems, and they usually take 30 to 60 minutes.

For UEFI firmware flashes, pros include resolving Secure Boot errors (per HP BIOS update guides), yet cons involve bricking risks if power interrupts; community posts on HP forums recommend backing up via Macrium Reflect first and running DISM /Online /Cleanup-Image /RestoreHealth post-update to dodge errors.

Monitor Disk Health Proactively

Your hard drive might fail quietly over time. The included tools run checks to spot problems early, before they cause startup failures.

1. Turn on S.M.A.R.T. monitoring in your BIOS settings. Reach it during startup by pressing F2 or the Del key, and make sure alerts are on. Ignoring these warnings, as seen in HP support threads where users lost data from undetected failures, can lead to irreversible damage.
2. Then, run chkdsk on your drive regularly. Start Command Prompt as administrator and type chkdsk C: /f /r. This tool finds and repairs problems. Schedule it to run once a week using Task Scheduler. Skipping these checks risks boot failures; for recovery, tools like Recuva or professional services from Seagate may be needed.

According to a 2022 Backblaze study, proactive S.M.A.R.T. checks prevent 80% of drive failures.

What If Basic Steps Fail to Resolve It?

Basic fixes flop? Dive deeper into command-line magic to resurrect your Windows boot on that HP laptop.

1. Boot your computer from a Windows installation USB drive to access the Command Prompt. During the setup, press Shift + F10.

   This opens it right away.

2. For EFI systems common on HPs, launch diskpart: type ‘diskpart’ to enter, then ‘list vol’ to identify volumes. Note the EFI partition (usually FAT32, ~100MB); select it with ‘sel vol X’ (replace X with number), then ‘assign letter=S’ to map it temporarily.

3. Next, repair boot: Exit diskpart, run ‘bootrec /fixmbr’, ‘bootrec /fixboot’, and ‘bootrec /rebuildbcd’.

4. If needed, use ‘bcdboot C:\Windows /s S: /f UEFI’ to recreate the bootloader, assuming C: is Windows and S: is EFI. Reboot to test- this resolves most partition mismatches per Microsoft support docs. (92 words)

Troubleshoot Advanced BIOS Options

Switching Secure Boot in UEFI mode could reveal boot paths that usual settings miss.

In an HP community case study, user Alden4 resolved legacy boot compatibility issues on an HP Pavilion by disabling Secure Boot via the F10 BIOS menu.

Here’s how:

1. Restart the PC and press F10 repeatedly during boot to enter BIOS Setup.
2. Go to the Security tab, find Secure Boot Configuration, and choose Disable.
3. Save changes with F10 and exit.

Upon reboot, the system recognized the legacy OS installer, which previously failed to load.

Alden4 shared a working installation of Windows 7 and received 15 kudos for the confirmed solution. HP moderators and several users with the same UEFI problems verified it.

Use Command Prompt for Repairs

Use Command Prompt for this job. Run diskpart to select and fix partitions fast.

1. Start Command Prompt as an administrator. Then type diskpart to open it.
2. Start with ‘list disk’ to identify your boot drive, then ‘select disk 0’ (replace 0 with your disk number).
3. Next, ‘list vol’ displays volumes-spot the EFI system partition (usually 100-500MB FAT32).
4. Select it with ‘select vol 1’, assign a letter via ‘assign letter=S’, and type ‘exit’ to leave diskpart.
5. For active marking on legacy BIOS, select the system volume and run ‘detail disk’ followed by ‘active’.
6. To rebuild the BCD per Microsoft’s recovery guide (docs.microsoft.com/en-us/windows-hardware/manufacture/desktop/bcdboot-command-line-options), use ‘bcdboot C:\Windows /s S: /f UEFI’ for EFI systems or ‘/f BIOS’ for MBR.
7. This restores boot files in under 5 minutes, resolving most startup failures.

Test with Diagnostic Software

Why guess at faults when HP’s built-in diagnostics can pinpoint drive errors in minutes?

To access them, restart your HP PC and repeatedly press F2 during boot to enter the HP PC Hardware Diagnostics UEFI interface. Go to Component Tests, choose Storage, and start the Quick or Extensive Hard Drive Test-the Extensive one checks for problems like bad sectors in less than 10 minutes on most drives.

1. For offline troubleshooting, download HP’s free USB Diagnostics Tool from support.hp.com
2. boot from the USB
3. and execute the Primary Hard Drive Test.

These quick checks, supported by HP’s reliability engineering, let people choose data recovery methods fast. They usually show if expert help like from Seagate Recovery is required.

Understanding Boot Process Fundamentals

The boot sequence kicks off in milliseconds, handing off from BIOS to OS loader-get it wrong, and nothing loads.

To trace this, start with power-on: the CPU resets, and firmware (BIOS or UEFI) runs POST to initialize hardware.

For modern systems like HP PCs compatible with Windows 11, UEFI mode activates Secure Boot and loads the EFI partition (FAT32, 100-500MB) via bootmgr.efim from the EFI System Partition-verify partitions with diskpart: run ‘list partition’ to see EFI (type ID 0xEF00), MSR (reserved, 16MB), and Windows NTFS (primary).

The loader then hands off to winload.efi, initializing ntoskrnl.exe and accessing the Windows folder (C:\Windows\System32) for drivers and user mode.

Misconfigurations, like disabled UEFI or missing EFI, halt here-use HP’s BIOS setup (F10) to enable TPM 2.0 for Win11 compliance per Microsoft specs.

Break Down BIOS vs UEFI Differences

Stuck in legacy BIOS mode on a modern laptop? Switching to UEFI opens doors to faster, secure booting.

Legacy BIOS, a 16-bit system from the 1980s, relies on MBR partitioning and lacks secure boot, often causing boot errors during Windows upgrades, as seen in HP forums where users report ‘no bootable device’ after installing Windows 10/11 on mismatched setups.

UEFI, its 64-bit successor, uses GPT for drives over 2TB and enables features like Secure Boot, reducing malware risks per Microsoft’s Secure Boot overview.

1. Restart into BIOS (F10 on HP laptops),
2. navigate to Boot Options,
3. select UEFI mode,
4. save and exit.

For upgrades, back up data first-Microsoft recommends converting to GPT via DiskPart if needed. This resolves 90% of HP boot issues, per support threads, ensuring smooth Windows 11 compatibility.

Examine MBR and GPT Partition Roles

MBR suits older drives under 2TB, but GPT’s GUID structure is essential for UEFI and larger disks in today’s setups.

Converting between MBR and GPT requires caution, often using the diskpart utility in Windows.

1. Open Command Prompt as an administrator to convert the disk. Enter diskpart. Type list disk to see the disks. Then select disk X, where X is the number for your disk. Type clean to wipe it clean. Save your data first, since this removes everything.
2. Follow with ‘convert gpt’ or ‘convert mbr’.

For boot stability, MBR offers reliable legacy BIOS booting via an active partition flagged in diskpart (‘active’ command), but risks corruption on large drives per Microsoft’s documentation.

GPT enhances UEFI stability with redundant partition tables, using an EFI System Partition (ESP) instead of active flags, reducing boot failures on drives over 2TB.

Studies from Storage Networking Industry Association note GPT’s 20% lower error rates in modern hardware comparisons.

Analyze Secure Boot Implications

Secure Boot blocks unsigned loaders, which is great for safety but can halt custom installs if not configured right.

For those interested in the benefits of UEFI’s Secure Boot from a Linux community perspective, this discussion on Reddit’s r/linux explains its usefulness in preventing malware while supporting custom setups.

The myth that Secure Boot always causes errors is overstated-Microsoft’s UEFI guidelines confirm 95% of issues stem from misconfiguration, not inherent flaws.

On HP laptops, fix this by entering the BIOS (press F10 during boot), going to System Configuration > Boot Options, and choosing Legacy Support Disable to work with Windows 11. Also enable Secure Boot.

For multi-boot setups like Linux alongside Windows, enroll custom keys via Microsoft’s Secure Boot DB tool or use signed GRUB2 loaders, as detailed in Ubuntu’s 22.04 docs.

HP forums report 80% success with these tweaks, avoiding errors in dual setups.

Test in a VM first for safety.

When Should You Seek Professional Help?

DIY limits hit hard when data’s at stake-call in pros if commands like bcdboot don’t revive your drive.

For HP notebook issues, start with official support.

Use the HP Warranty Checker tool at support.hp.com: enter your serial number to verify coverage instantly-warranties often last 1-3 years with options for extension. Contact HP via 1-800-474-6836 (US, Mon-Fri 7am-10pm ET) or live chat on their site for diagnostics.

Community FAQs on forums.hp.com recommend escalating if boot failures persist beyond firmware updates, like repeated black screens. Beware scammers posing as HP techs demanding payment-official support never charges upfront.

Premium users get onsite service within 48 hours for hardware faults, per HP’s 2023 service guidelines.

Evaluate Data Recovery Needs

Critical files trapped on a dead drive? Assess if recovery costs outweigh recreating documents before proceeding.

1. If recovery seems viable, prioritize non-destructive methods to avoid further damage.

2. Start with free tools like TestDisk or Recuva for logical errors-TestDisk can repair partitions without overwriting data, succeeding in 70% of cases per forensic studies from the SANS Institute.

3. If DiskPart causes issues, start your computer from a Linux live USB. Then use the dd command in the terminal to copy the drive: dd if=/dev/sda of=backup.img bs=4M.

4. This clones the entire disk to an external USB before any wipes. HP Community forums report users salvaging family photos from failed HDDs this way, often in under an hour with a 1TB external drive.

5. If hardware failure is suspected, consult pros like DriveSavers, but DIY imaging first saves hundreds.

Assess Hardware Replacement Costs

Replacing a hard drive runs $50-200 plus labor, but skipping it might mean total laptop failure down the line.

To avoid this, monitor for symptoms like slow boots or error messages.

Consider the case from Alden4’s Reddit thread, where a failing HDD caused endless boot loops on an HP Pavilion, risking data loss.

Pre-swap, the laptop was unusable daily; post-upgrade to a Samsung 860 EVO SSD ($60), boot times dropped from 2 minutes to 10 seconds, resolving issues entirely.

For DIY:

1. Backup with free Macrium Reflect,
2. clone the drive (1-2 hours),
3. and swap using a $10 screwdriver kit-total under $80.

HP support charges $150 to $300 for a professional replacement, which includes diagnostics. This works well if you lack technical knowledge.

DIY saves money but requires caution to avoid voiding warranties.

Consider Warranty and Support Options

Still under HP warranty? Use free repairs instead of making home changes that could cancel your coverage.

1. To capitalize on this, first verify your coverage on HP’s official support site (support.hp.com) by entering your device’s serial number- a quick process that displays expiration dates and terms.
2. Next, contact HP via their 24/7 chat or phone support (1-800-474-6836 in the US) for diagnostics; technicians often resolve issues remotely using tools like HP Support Assistant software.
3. Avoid common pitfalls like unauthorized BIOS flashes, which void warranties per HP’s policy (detailed in their standard limited warranty document).
4. For hardware faults, schedule free pickup via UPS.

This official route, backed by HP’s 90-day satisfaction guarantee, prevents scams in unofficial forums and ensures no out-of-pocket costs.

Macro Semantics: Broader OS Error Contexts

This boot error isn’t isolated-it’s part of a web of OS glitches that Windows users face across setups.

Common culprits include malware corrupting the Boot Configuration Data (BCD), as seen in a 2022 Microsoft Security Intelligence Report where 15% of boot failures traced to viruses like WannaCry variants. In multi-boot environments, GPT partition mismatches often trigger errors, especially on HP systems with Secure Boot enabled-reference HP’s support doc KM013456 for BIOS resets.

1. To solve the problem, restart your computer while pressing the Shift key to reach Windows Recovery Environment.
2. Next, open Command Prompt and enter bootrec /rebuildbcd.
3. For deeper fixes, use SFC /scannow to repair system files or third-party tools like EasyBCD ($10) to rebuild boot menus.

These steps resolve 70% of cases per forums like Tom’s Hardware, preventing escalation to full reinstalls.

Compare with Blue Screen Errors

Blue screens crash mid-run, while ‘OS not found’ halts at startup-both signal deep system unrest but need different fixes.

Blue Screen of Death (BSOD) errors, as detailed in HP support forums, often stem from faulty drivers or hardware conflicts, like outdated graphics drivers crashing during gaming.

Open Command Prompt and run chkdsk /f /r to find disk errors. Or open Device Manager and roll back recent updates.

These actions fix problems quickly without deleting data, but faulty hardware can lead to repeated restarts.

Conversely, ‘OS not found’ arises from boot configuration slips, such as corrupted BCD files from improper shutdowns.

Boot from Windows media. In recovery, open the command line and run ‘bootrec /fixmbr’ and ‘bootrec /rebuildbcd’ to fix boot problems. This handles software problems well but not disk problems, according to Microsoft documentation.

Shared diagnostics: Event Viewer logs both for error codes, guiding targeted repairs.

Link to Malware and Virus Impacts

Malware sneaks in to corrupt boot sectors, turning a simple virus scan into a full recovery ordeal.

In online forums like Reddit’s r/techsupport, users shared harrowing tales of ransomware wiping EFI system partitions on Windows PCs, leading to the dreaded ‘Bootmgr is missing’ error from a corrupted Boot Configuration Data (BCD). The culprit? Malicious scripts targeting UEFI firmware.

To recover, boot from a Windows installation USB created with Microsoft’s Media Creation Tool-download it from their official site, select ‘Create installation media,’ and follow prompts.

1. Once you get to the Recovery Environment, start Command Prompt and type the command ‘bootrec /rebuildbcd’.
2. This fixes the BCD.

For prevention, enable BitLocker encryption (as per Microsoft’s security guidelines) and run regular scans with tools like Malwarebytes.

• Back up to external drives weekly to avoid data loss, a lesson echoed in countless FAQ threads.

Connect to Multi-Boot System Challenges

Juggling Windows and Linux? Multi-boot setups often scramble priorities, leading straight to OS detection fails.

path \EFI\ubuntu\grubx64.efi for Linux. HP users, disable Fast Boot and Secure Boot in BIOS to handle multi-drive quirks, resolving 80% of detection issues per Ubuntu forums.

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To regain control, enter BIOS (press F10 on Dell, F2 on HP, or Del during startup) and set boot order to prioritize your EFI system partition-typically the first drive with GRUB or Windows Boot Manager.

For GPT compatibility, verify partitions via Disk Management (Windows) or GParted (Linux); convert MBR to GPT using mbr2gpt.exe if needed, as per Microsoft’s documentation.

To correct boot entries for Linux, run Command Prompt as an administrator.

1. Type bcdedit /enum to see the list.
2. Then type bcdedit /set {bootmgr} path EFIubuntugrubx64.efi.

HP users, disable Fast Boot and Secure Boot in BIOS to handle multi-drive quirks, resolving 80% of detection issues per Ubuntu forums.