There are several reasons to use UEFI instead of BIOS. I won't go into details regarding that. But there are some cases when you already have a fully functional Windows installation running on BIOS and you don't want to start all over again. Sadly, there
are no tools that performs this job. And I found there is not too much documentation regarding how this can be performed either, or even how this should work. Since after some digging and trial-and-error I was able to perform the operation, I will post the
instructions for anyone who needs it.
If you have any doubt, feel free to contact me. I will answer whatever (and whenever) I can.
Convert a Windows 7/8 BIOS (MBR) installation to UEFI (GPT) without moving, copying or loosing data.
Steps were performed on Windows 8. Some steps in Windows 7 may have different menus, but the options and results are the same.
There is an Easier way!
Use a Backup tool Make a backup of your current Win8 system, (i used Acronis, but Ghost and other should work.
Using a bootup tool (acronis boot disk, or other usb/ODD startup tools) Format the disk in GDP.
Then adjust your bios settings for UEIF Start-up.
Install Fresh copy of Windows 8, or Windows 7* on the newly formatted Hard Drive.(Check the BIOs for a UEIF Startup option for your installation media there should be two boot options for your media now).
After Windows has installed, Check Disk Manager to see that you have the 100mb EFI partition.
Then use your backup tool to restore your original Windows installation over the new system. Making sure to uncheck any options for restoring the "MBR" .
Bam ya done.
*Like many people, i don't have a Windows 8 install disk, So i used a Windows 7, install disk, then used my Windows 8 install files to upgrade the newly installed Windows 7. This worked because the Windows 7 install disk was x64.
Make sure there is enough space before your main partition to create the two partitions in step 13. I had only 100MB and I got stuck there.
I was able to shrink and move my main partition thanks to a live-CD I had lying around, and complete the instructions successfully.