How to Change Legacy to UEFI without Reinstalling Windows

Need to change Legacy to UEFI

Two firmware interfaces for computers are UEFI and Legacy. They function as an intermediary between the operating system and the substrate firmware. The hardware components are initialized and the operating system installed on the disk is initiated by the interface (Legacy or UEFI) during the computer's launch process. However, a significant number of users are uncertain as to the distinction between the two and which is more advantageous.

In general, UEFI is superior to Legacy BIOS due to the following benefits:

▍Upgrade to increase the amount of available disk space

The MBR disk is utilized by legacy BIOS, whereas the GPT hard drive is employed by UEFI. The primary distinction between the two partition styles is that MBR is limited to a maximum of 2TB for hard drives, whereas GPT can support up to 9.4ZB. This significantly transcends the 2TB disk capacity limit.

▍Enhance boot time

UEFI has the potential to significantly improve the speed of your computer and reduce the startup time, which will be particularly beneficial when you install a large hard drive on your device.

▍Enhanced security

In contrast to BIOS, the Secure Boot feature is included in the UEFI. It can significantly enhance the security of the launch process by preventing the UEFI drivers or OS boot loaders from loading if they lack an acceptable digital signature.

Therefore, it is straightforward to deduce that the UEFI is equivalent to Legacy, but it is more effective. Change from Legacy to UEFI can be a worthwhile upgrade for those who are using a 64-bit Windows system.

Furthermore, Microsoft asserts that the UEFI boot mode and GPT partition table are also necessary for the upgrade from Windows 10 to Windows 11.

Is UEFI supported by my PC?

Despite the fact that UEFI is more effective than Legacy, not all devices permit users to transition to UEFI. You must be aware of certain prerequisites. In the event that your Windows hardware malfunctions, a black screen may result.

1. Initially, verify that your Windows machine is capable of supporting UEFI. UEFI secure boot is generally supported by all motherboards that were released after 2014. However, this is not always the case. Consequently, it is necessary to verify the eligibility of your device on an individual basis.

2. Windows 10 v1703 or a later version should be utilized. If you are uncertain, press Win + R, enter "winver," and press Enter. The second line should display "version 1703" or a higher version.

3. The disk you are endeavoring to convert should consist of no more than three partitions. If the number of partitions on your Windows 10 installation disk exceeds three, you may either merge or eliminate them. A "Disk Layout Validation Failed" error will be generated if this is not done. While it is possible to resolve this error, it is advisable to avoid it.

Can I change from Legacy to UEFI without reinstalling Windows?

The Legacy system necessitates that Windows launch from an MBR disk, whereas UEFI necessitates a GPT boot disk. Consequently, it is necessary to convert the MBR to GPT when transitioning from Legacy to UEFI. In the interim, the conversion of the target disk from MBR to GPT will result in the loss of all data, including the operating system, if the Windows built-in tools are employed.

Luckily, there are some professional and safe tools like AOMEI Partition Assistant, a partition software, that can tap into the disk potential and manage partitions efficiently. It allows you to convert the disk from MBR to GPT without deleting partitions or losing data in Windows 11/10/8/7.

Step 1. Right-click on the system disk and select Convert to GPT or click the disk and choose Convert to GPT from the right column.

Step 2. Choose your OS disk and click "OK" to continue your operation.

Step 3. Click “Apply” > "Proceed" to apply the change.

Change from Legacy to UEFI in BIOS

1. Press F2 or other shortcuts continuously when prompted to enter BIOS menu. From the BIOS Main menu screen, select Boot.

2. From the Boot screen, select UEFI/BIOS Boot Mode, and press Enter. Then the UEFI/BIOS Boot Mode dialog box appears.

3. Use the up and down arrows to select Legacy or UEFI, and then press Enter.

4. To save the changes and exit the screen, press F10.

For newer motherboards, the setup is simpler. Please make sure that UEFI support is turned on (Launch CSM enabled) then it will work.

Conclusion

If your operating system (OS) is compatible, it is recommended that you switch from Legacy boot mode to UEFI boot mode. Since there is no need to reinstall Windows 11, 10, 8, or 7, the entire process is efficient and uncomplicated, as you can see from the image.