Enter firmware setup, switch the machine to UEFI boot mode, turn on Secure Boot only if your install calls for it, and use GPT for the Windows disk or USB media. If Windows is already installed in legacy mode, convert the disk before you change the firmware setting. Skip that order, and the PC may stop booting or refuse the installer.

What you'll need

  • Administrator access to Windows
  • A keyboard that works at startup, or access to Windows Advanced startup
  • Your BitLocker recovery key if device encryption or BitLocker is on
  • A USB install drive only if you are installing or repairing Windows from external media

How do you enter UEFI setup?

How do you enter UEFI setup?
Windows recovery screen showing the UEFI Firmware Settings option

Use the startup key first, since it is the shortest path to firmware setup. If Windows boots too fast, use Advanced startup from inside Windows. Dell says there are two reliable ways to open BIOS setup on a Dell computer, and Dell recommends tapping F2 about once per second as soon as the logo appears. Microsoft lists common keys such as Esc, Delete, F1, F2, F10, F11, and F12. (Microsoft Learn)

  1. Shut down the PC completely.
  2. Power it on and tap the vendor key repeatedly: F2, Delete, Esc, F10, or F12.
  3. If Windows starts first, open Settings > System > Recovery > Advanced startup > Restart now.
  4. Choose Troubleshoot > Advanced options > UEFI Firmware Settings > Restart.
  5. Wait for the firmware screen before Windows loads.

If a laptop with Fast Startup powers on so quickly that the key window disappears, the Windows route is more reliable than timing the logo screen. If the keyboard is wireless, switch to a wired keyboard for the first boot attempt, because early firmware menus can miss Bluetooth input.

What if the menu is missing?

If UEFI Firmware Settings does not appear under Advanced options, the system may not expose that path, or startup timing may be blocking it. Try a full shutdown, a wired keyboard, and a direct vendor key press first. If device encryption is active, a recovery prompt can also interrupt the handoff.

How do you set boot mode to UEFI?

How do you set boot mode to UEFI?
A BIOS settings screen shows Windows UEFI mode selected

Find the boot-mode control and move it to UEFI-only or UEFI-first. Vendor labels vary. You may see Boot Mode, UEFI/Legacy, CSM, Launch CSM, Legacy Support, or Boot Device Control. Intel says Boot Device Control can be set to UEFI Only. That is the target for a clean UEFI boot path.

  1. Open the firmware menu.
  2. Go to the Boot, Advanced, or Startup tab.
  3. Set Boot Mode or Boot Device Control to UEFI Only or UEFI.
  4. Disable CSM, Launch CSM, or Legacy Support if the menu offers that switch.
  5. Move the UEFI USB entry to the top if you are installing from a flash drive.
  6. Save changes and reboot.

Do not assume the change took effect just because the menu accepted it. If Windows still starts in legacy mode afterward, the disk layout or boot entry still points the wrong way. Microsoft says boot menus can show separate entries such as UEFI: USB Drive and BIOS: Network/LAN; choose the UEFI entry, not the legacy one.

Do you need GPT for UEFI mode?

For a new UEFI install, yes. Intel says UEFI mode is compatible with GPT, and legacy BIOS mode is compatible with MBR. If Windows is already installed on an MBR disk, you usually need to convert that disk before changing firmware mode. Microsoft’s MBR2GPT tool is the built-in path for that job after Windows is installed. (Intel)

How do you turn on Secure Boot?

Secure Boot sits inside UEFI and can be left off or turned on depending on your install plan. If you change Secure Boot or boot mode while BitLocker is active, Dell warns that BitLocker can ask for a 48-digit recovery key. Suspend BitLocker first, then enable Secure Boot, save, and confirm that the setting survives the reboot.

  1. Open Control Panel > BitLocker Drive Encryption.
  2. Select Suspend protection before changing firmware settings.
  3. Return to firmware setup.
  4. Open the Security, Boot, or Authentication menu.
  5. Set Secure Boot to Enabled.
  6. Save changes and restart.
  7. After Windows loads, check that Secure Boot still reads on.

If a desktop enters recovery after a Secure Boot change, the likely cause is a BitLocker reaction to the firmware change, not a failed disk. Enter the recovery key, then return to Windows and suspend BitLocker before making any further firmware edits.

UEFI setup checklist

Goal Exact firmware setting to change Where it usually appears by vendor naming BitLocker should be suspended? How to verify success in Windows after reboot
Enter UEFI setup Startup key or Windows Advanced startup BIOS, UEFI, or System Setup No Firmware screen opens before Windows starts
Switch to UEFI boot Boot Mode, UEFI/Legacy, CSM, Legacy Support, Boot Device Control Boot, Advanced, Startup Yes if encryption is on System Information shows UEFI boot mode
Enable Secure Boot Secure Boot Security, Boot, Authentication Yes Windows reports Secure Boot as on
Boot a USB installer in UEFI mode UEFI USB entry or boot order Boot Menu, Boot Priority No for the installer boot itself Boot menu shows a UEFI-prefixed USB entry
Convert an installed Windows disk for UEFI MBR2GPT in Windows, then firmware mode change Command line plus firmware Yes Disk uses GPT and Windows starts normally in UEFI mode

How do I know if Windows is booting in UEFI mode?

Open System Information and check BIOS Mode. If it says UEFI, the machine booted the right way. If it says Legacy, the firmware change did not carry through, or the disk still points to a legacy boot path. This check is commonly available in Windows 10 and Windows 11.

  1. Press Windows key, type System Information, and open it.
  2. Look for BIOS Mode.
  3. Confirm it says UEFI, not Legacy.
  4. Open msinfo32 if you prefer the Run box.
  5. Check Secure Boot State on the same page if needed.

What do I do if UEFI Firmware Settings is missing?

What do I do if UEFI Firmware Settings is missing?
A hand presses a restart button beside a warning-filled computer monitor

If the Windows menu is missing, use the startup key path, then rule out Fast Startup and encryption prompts. Some systems hide the Windows recovery entry even though the firmware still accepts a vendor key. A missing menu does not mean the machine lacks UEFI; it often means Windows cannot hand off to setup on that model.

  1. Open Control Panel > Power Options > Choose what the power buttons do.
  2. Turn off Turn on fast startup.
  3. Fully shut down the PC.
  4. Use the vendor startup key again.
  5. If that fails, connect a wired keyboard and retry.
  6. On Dell systems, use Settings > System > Recovery > Advanced startup > UEFI Firmware Settings > Restart if the entry appears later.

How do you switch from legacy BIOS to UEFI?

Convert the Windows disk first if it is still MBR, then switch firmware to UEFI-only. Microsoft’s MBR2GPT tool applies after Windows is already installed. If the conversion succeeds, reboot into firmware and disable legacy support or CSM. That sequence avoids the common boot-mode mismatch.

  1. Back up important files.
  2. Suspend BitLocker.
  3. Open an elevated Command Prompt and run the conversion check: mbr2gpt /validate /allowFullOS.
  4. If validation passes, run mbr2gpt /convert /allowFullOS.
  5. Reboot into firmware and set UEFI-only mode.
  6. Boot back into Windows and confirm BIOS Mode says UEFI.

Common mistakes

The same few mistakes cause most failures. They are easy to avoid once you know the order.

  • Changing Secure Boot before suspending BitLocker.
  • Picking the legacy USB entry instead of the UEFI one.
  • Leaving CSM or Legacy Support on after a UEFI switch.
  • Assuming the menu change worked without checking Windows System Information.
  • Running MBR2GPT on a disk that does not fit the tool’s requirements.

A common first-time mistake is to open firmware, enable Secure Boot, and stop there. If the disk is still MBR and Windows was installed in legacy mode, the PC may continue booting the old path or fail to start at all. Change the disk layout and boot mode together.

To avoid trouble, suspend BitLocker before firmware edits, change one boot setting at a time, and verify BIOS Mode after every reboot.

Frequently asked questions

How do I set up UEFI on my PC?

Enter firmware with the startup key or Advanced startup, set the boot mode to UEFI-only, and enable Secure Boot if your install requires it. If Windows already exists on an MBR disk, convert it with mbr2gpt /convert /allowFullOS before you change the firmware mode.

How do I enter UEFI setup from Windows?

Open Settings > System > Recovery > Advanced startup > Restart now, then choose Troubleshoot > Advanced options > UEFI Firmware Settings > Restart. If that item is missing, use the vendor startup key instead. The same source lists the same route on supported systems.

How do I turn on Secure Boot in UEFI?

Suspend BitLocker first, then open firmware and find Secure Boot under Security, Boot, or Authentication. Set it to on, save changes, and check System Information after reboot. If BitLocker was active, keep the recovery key ready.

How do I know if Windows is booting in UEFI mode: press Windows key, open?

Press Windows key, open System Information, and check BIOS Mode. UEFI means the machine is booting the modern firmware path. Legacy means the firmware or disk still uses the older path and needs another adjustment.

How do I boot a USB drive in UEFI mode?

Open the boot menu and pick the entry that starts with UEFI:, not the plain USB or BIOS entry. Microsoft says boot menus can show separate UEFI and BIOS choices. If needed, move the UEFI USB option to the top of the boot priority list.