To enable UEFI, enter your computer’s firmware settings, choose UEFI instead of Legacy or CSM boot, and save the change. The important qualification is that a Windows installation started in Legacy mode often uses an MBR system disk; switching firmware first can then leave Windows unbootable. Check the current boot mode and partition style before changing anything, and use Microsoft’s MBR2GPT process when conversion is required.
What UEFI is—and what “BIOS” means on a modern PC
UEFI (Unified Extensible Firmware Interface) is the firmware that starts before Windows. It initializes hardware, selects a bootloader and exposes settings for storage, processor features, virtualization, security and other devices. Many manufacturers still label this setup screen “BIOS,” even when the firmware itself is UEFI-based. In practical terms, “enable UEFI in BIOS” usually means changing the boot mode from Legacy BIOS or Compatibility Support Module (CSM) to native UEFI.
As an Amazon Associate I earn from qualifying purchases.
UEFI is not a Windows application and it is not enabled from the normal desktop. You change it in firmware setup, then Windows must be installed and configured in a way that can boot through UEFI. UEFI and Secure Boot are related, but they are separate settings: UEFI selects the firmware boot method, while Secure Boot verifies signatures on boot-stage software.
Do these 3 things before closing this tab:
1Repair Windows errors before they cause bigger problems2Scan for outdated or missing drivers - takes under a minute3Clear out junk files and repair common Windows errorsCheck compatibility before changing a firmware setting
Do these checks while Windows still starts normally. They prevent the most common mistake: changing one firmware option without preparing the disk or recording the original configuration.
#1 Best Overall
- AMD Socket AM4: Ready to support AMD Ryzen 5000 / Ryzen 4000 / Ryzen 3000 Series processors
- Enhanced Power Solution: Digital twin 10 plus3 phases VRM solution with premium chokes and capacitors for steady power delivery.
- Advanced Thermal Armor: Enlarged VRM heatsinks layered with 5 W/mk thermal pads for better heat dissipation. Pre-Installed I/O Armor for quicker PC DIY assembly.
- Boost Your Memory Performance: Compatible with DDR4 memory and supports 4 x DIMMs with AMD EXPO Memory Module Support.
- Comprehensive Connectivity: WIFI 6, PCIe 4.0, 2x M.2 Slots, 1GbE LAN, USB 3.2 Gen 2, USB 3.2 Gen 1 Type-C
Record the PC model and firmware support
Write down the manufacturer, exact model and Windows edition. Firmware menus, option names and recovery procedures vary by model. If the computer is managed by an organization, its boot policy may also be controlled centrally. Confirm in the manufacturer’s documentation that the device supports UEFI before planning a switch.
Check the current boot mode
- Press
Windows+R, typemsinfo32, and pressEnter. - In System Information, find BIOS Mode. It normally reports UEFI or Legacy.
- Record the value before making any change. If it already says UEFI, you generally do not need to switch boot mode; your task may instead involve Secure Boot or another firmware option.
Check the system disk’s partition style
UEFI Windows boot normally uses a GUID Partition Table (GPT). Legacy installations commonly use a Master Boot Record (MBR). In Disk Management, right-click the disk containing the Windows partition, choose Properties, open the Volumes tab and read Partition style. A data disk can have a different style; the disk that contains the Windows boot files is the one that matters.
Prepare recovery information
- Back up important files before changing firmware or partition configuration. A conversion designed to preserve data is not a substitute for a backup.
- If BitLocker or device encryption is enabled, locate the recovery key and keep it available. Firmware and boot changes can trigger a recovery prompt.
- Plan how you will return to the original firmware setting if Windows does not start. Do not guess at unrelated options after a failed boot.
Open UEFI firmware settings from Windows
On supported Windows versions, the most consistent route avoids guessing a startup key:
Recommended Free Tools
- Open Settings.
- Go to System > Recovery.
- Under Advanced startup, select Restart now.
- At the recovery menu, choose Troubleshoot > Advanced options > UEFI Firmware Settings > Restart.
If UEFI Firmware Settings is missing, the manufacturer may use a different recovery design, the installation may be running in Legacy mode, or the firmware may not expose the option to Windows. Consult the support documentation for the exact model. Do not assume that a key such as F2, Delete, Esc or F12 works on every computer; startup keys differ by manufacturer and model.
Decide whether a disk conversion is necessary
| Current BIOS Mode | Windows system-disk style | What to do before changing boot mode |
|---|---|---|
| UEFI | GPT | Leave boot mode on UEFI. Enable Secure Boot only if your goal requires it. |
| UEFI | MBR | Do not assume the disk is suitable for every UEFI configuration. Verify the installation and manufacturer guidance before changing anything. |
| Legacy or CSM | MBR | Usually convert the eligible Windows disk to GPT first, then change firmware to UEFI. |
| Legacy or CSM | GPT | Check the existing boot files and model documentation. A mode change may be possible, but do not toggle settings without confirming that Windows has a UEFI boot path. |
The exact combination matters more than the label on the setup screen. A Legacy/CSM Windows installation commonly relies on MBR boot code. If you simply disable Legacy and select UEFI, the firmware may not find a bootable Windows entry even though all personal files remain on the disk.
Rank #2
- AM4 socket: Ready for AMD Ryzen 3000 and 5000 series, plus 5000 and 4000 G-series desktop processors.Bluetooth v5.2
- Best gaming connectivity: PCIe 4.0-ready, dual M.2 slots, USB 3.2 Gen 2 Type-C, plus HDMI 2.1 and DisplayPort 1.2 output
- Smooth networking: On-board WiFi 6E (802.11ax) and Intel 2.5 Gb Ethernet with ASUS LANGuard
- Robust power solution: 12+2 teamed power stages with ProCool power connector, high-quality alloy chokes and durable capacitors
- Renowned software: Bundled 60 days AIDA64 Extreme subscription and intuitive UEFI BIOS dashboard
Convert an eligible Windows disk with MBR2GPT
Microsoft’s MBR2GPT utility can validate and convert an eligible Windows system disk from MBR to GPT without deleting the disk’s data. Eligibility is conditional, so validation must succeed before conversion. Microsoft’s test guidance specifies, for the scenario it documents, no more than three primary MBR partitions and a device that supports UEFI. Other layout or boot problems can also make validation fail.
1. Suspend BitLocker protection
Microsoft’s guidance requires BitLocker protection to be suspended for conversion. Use the BitLocker controls in Windows or your organization’s approved management procedure, and confirm that you have the recovery key before continuing. Suspension is not the same as decrypting the drive; follow the current Microsoft instructions for resuming protection after the firmware change.
Quick wins for a faster PC:
Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Clear out junk files and repair common Windows errorsFree Scan →2. Validate the disk
Open an elevated Command Prompt or Windows Terminal and run the validation form documented for your Windows installation. A common example for the first physical disk is:
mbr2gpt /validate /disk:0 /allowFullOSReplace the disk number only after you have positively identified which disk contains Windows. The command should report that validation completed successfully. If it fails, stop and correct the reported layout or consult Microsoft’s current MBR2GPT guidance; do not proceed by forcing a conversion.
3. Convert only after validation succeeds
After a successful validation and a verified backup, run the conversion form:
Rank #3
- AMD AM4 Socket and PCIe 4.0: The perfect pairing for 3rd Gen AMD Ryzen CPUs
- Ultrafast Connectivity: 1x PCIe 4.0 x16 SafeSlot, WiFi 6 (802.11ax), 1Gb LAN, dual M.2 slots (NVMe SSD)—one with PCIe 4.0 x4 connectivity, USB 3.2 Gen 2 Type-A , HDMI 2.1 (4K at 60HZ), D-Sub & DVI
- Comprehensive Cooling: VRM heatsink, PCH heatsink, hybrid fan headers and Fan Xpert 2 utility
- 5X Protection III: all-round protection with LANGuard, DRAM overcurrent protection, overvoltage protection, SafeSlot Core safeguards and stainless-steel back I/O
- Boosted Memory Performance: ASUS OptiMem proprietary trace layout allows memory kits to operate at higher frequencies with lower voltages to maximize system performance.
mbr2gpt /convert /disk:0 /allowFullOSMBR2GPT creates the GPT structures and the UEFI boot files while preserving the existing Windows volume and data when the operation completes successfully. It does not make an unsupported disk safe, repair every boot problem or remove the need to change firmware afterward. Read the utility’s output and retain any error details.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
4. Reboot directly into firmware
Do not let the machine repeatedly attempt the old Legacy path after conversion. Use the Windows recovery route or the documented model-specific startup key to enter setup on the next restart. Change the firmware boot mode only after the conversion has completed.
Change Legacy or CSM to UEFI in firmware
Firmware interfaces differ, but the decision is usually represented by one of these labels: Boot Mode, UEFI/Legacy Boot, CSM, Legacy Support or Compatibility Support Module.
- Enter firmware setup through Windows Recovery or the manufacturer’s documented startup procedure.
- Open the Boot, Startup or similarly named page.
- Set the boot mode to UEFI, or disable Legacy/CSM if the interface presents a choice.
- Place the UEFI Windows Boot Manager entry first when the menu offers it. Some firmware displays the disk model and “Windows Boot Manager” as separate choices; choose the Windows Boot Manager entry for the system disk.
- Save changes and exit using the firmware’s own command, often labeled Save Changes and Exit.
Change only the setting required for the task. Avoid altering storage-controller mode, overclocking, boot-security keys or unrelated hardware options at the same time. If Windows starts normally, the mode change was accepted. If it does not, return to firmware and restore the previous mode, then use the manufacturer’s support procedure rather than trying random combinations.
Enable Secure Boot only when you need it
Secure Boot is a UEFI security feature, not a synonym for UEFI. Microsoft describes it this way: “Secure Boot is a security feature that helps prevent malicious software from loading when a Windows PC starts up.” It checks boot-stage software signatures against trusted certificates before allowing startup components to run.
Rank #4
- AMD Socket AM4: Ready to support AMD Ryzen 5000/4000/3000 Series Processors
- Enhanced Power Solution: Digital 3+3 VRM Design and premium chokes and capacitors for steady power delivery.
- Advanced Thermal Armor: Chipset heatsinks for better heat dissipation.
- Boost Your Memory: Compatible with DDR4 and supports 4 DIMMS with Extreme Memory Profile support.
- Comprehensive Connectivity: 1x Ultra Durable PCIe 4.0 x16 slot, 1x PCIe 4.0 M.2 slot, 1x PCIe 3.0 M.2 slot, 4x USB 3.2 Gen 1 ports for hassle-free setup.
Some systems require UEFI to be selected before Secure Boot can be enabled. Microsoft’s guidance also notes that Legacy/CSM must be switched off and UEFI must be the first or only boot option on certain devices. The menu may be under Security, Boot, Authentication or a vendor-specific heading.
- Confirm that Windows is already booting in UEFI mode.
- Enter firmware setup and locate Secure Boot.
- Set it to Enabled, accepting any prompt to load the manufacturer’s default keys if the documentation directs you to do so.
- Save and restart.
Do not claim that Secure Boot is mandatory for every UEFI use case. It is appropriate when required by a Windows feature, an organizational policy or a security objective, but enabling UEFI alone may be the complete task. Custom bootloaders, older operating systems and some hardware tools may need additional compatibility work before Secure Boot can be used.
Verify the result in Windows
After the restart, verify both the boot mode and any security setting you changed:
- Run
msinfo32again and check BIOS Mode. It should report UEFI after a successful switch. - In the same window, review Secure Boot State if you attempted to enable Secure Boot. It should report On only when the firmware accepted the setting and Windows recognizes it.
- Open Windows Security and review the device-security or Secure Boot status shown for your Windows version.
- Confirm that storage volumes, network access, external devices and any business applications you need still work.
- Resume BitLocker protection using the approved Windows or organizational procedure once the system is stable.
If BIOS Mode still says Legacy, the machine may have restarted through the old path, the firmware setting may not have been saved, or the installation may not contain a usable UEFI boot entry. Return to the model-specific documentation instead of repeating the change blindly.
Free tools Windows power users keep installed
One-click scans. No signup required.
Troubleshoot a failed boot or recovery prompt
“No boot device” or Windows Boot Manager is missing
Enter firmware and check that UEFI is selected and that the correct Windows Boot Manager entry is first. If the disk was previously an MBR Legacy installation, restore the old mode so Windows can start, then review MBR2GPT validation and the manufacturer’s instructions. A missing entry is not proof that the files were erased.
Best Value
- AMD Socket AM5: Supports AMD Ryzen 9000/Ryzen 8000/Ryzen 7000 Series Processors
- DDR5 Compatible: 4 SMD DIMMs with AMD EXPO and Intel XMP Memory Module Support
- Unparalleled Performance: 12 plus2 plus2 Phases Digital VRM Solution
- Advanced Thermal Design and M.2 Thermal Guard: To Ensure VRM Power Stability and M.2 SSD Performance
- Stable Connectivity: 1 x PCIe 5.0 plus 2 x PCIe 4.0 M.2, USB 3.2 Gen 2x2 Type-C
Windows starts BitLocker recovery
Provide the recovery key you saved before the change. Firmware mode and Secure Boot state are boot measurements that can cause a recovery challenge. Once Windows starts, verify the mode, confirm that Secure Boot has the intended state and resume protection only after the configuration is stable.
Secure Boot cannot be enabled
Check that the system is booting in UEFI mode, Legacy/CSM is disabled and the firmware’s UEFI boot option is first. Some computers require restoring factory Secure Boot keys or updating firmware according to the manufacturer’s instructions. Do not delete keys or switch to a custom-key mode unless the documentation specifically calls for it.
MBR2GPT validation fails
Read the validation output and check the partition count, free space and boot configuration against Microsoft’s current eligibility rules. The documented test scenario allows at most three primary MBR partitions, but other conditions can also prevent conversion. Keep the machine in its working Legacy mode until the problem is resolved. If the disk is not eligible, a clean Windows installation in UEFI/GPT mode may be an alternative, but that path requires a separate backup, reinstall and application plan.
The Tool Desk
Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →Outbyte Driver Updater FREEFix the driver behind crashes, sound loss and screen glitchesFind Drivers →Certificate-related Secure Boot recovery scenarios
Microsoft’s Secure Boot support guidance published in March 2026 describes a specific recovery workflow in which a FAT32-formatted USB drive carries SecureBootRecovery.efi. That removable media is optional and task-specific; it is not needed merely to enter UEFI firmware or change from Legacy to UEFI. Use it only when Microsoft’s current instructions for your certificate or boot-recovery situation explicitly require it.
Secure Boot certificate servicing is an active area of Microsoft support guidance. Certificate updates, trust stores and recovery behavior can change over time, so check the current Microsoft instructions and the computer manufacturer’s notes before applying a certificate-related fix. Do not treat a generic USB procedure as a universal Secure Boot repair.
Quick Recap
Choose the safest path for your situation
| Your goal | Recommended path | Main risk to avoid |
|---|---|---|
| Use a feature that requires native UEFI | Check BIOS Mode and disk style; convert an eligible MBR Windows disk, then select UEFI. | Toggling firmware first and losing the Windows boot path. |
| Turn on Secure Boot | Confirm UEFI boot, disable Legacy/CSM, then enable Secure Boot and verify its state. | Assuming Secure Boot and UEFI are the same setting. |
| Keep an existing UEFI installation secure | Leave boot mode on UEFI and change only Secure Boot or the specific security option required. | Changing storage or unrelated firmware settings unnecessarily. |
| Recover from a failed change | Restore the previous boot mode, use the recovery key if requested, and follow model-specific support instructions. | Repeated trial-and-error changes that obscure the original configuration. |
Key points to remember
- “BIOS” in a menu may refer to modern UEFI firmware.
- Use the Windows Recovery path when available, but rely on the manufacturer for model-specific menus and startup keys.
- Legacy/CSM Windows installations commonly use MBR; native UEFI Windows boot generally uses GPT.
- Validate MBR2GPT eligibility before converting, keep a backup and suspend BitLocker protection as Microsoft directs.
- Secure Boot is an independent security control. Enable it only after UEFI boot works and only when your use case calls for it.
- Verify BIOS Mode and Secure Boot State in Windows after every change.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
