Solved Cannot install win 8.1 x64, on MBR HDD running Win 7 on UEFI

SherlockHomie

New member
Local time
1:48 PM
Messages
2
Hey,
I currently have a Custom built computer, based on gigabyte GA-990XA-UD3 mobo.
I have a Segate Barracuda 1TB HDD that is currently in MBR format, and is full of data.
The mobo uses UEFI.
Now, I have read that uefi REQUIRES us to use a GPT HDD to boot up Widows 7/8/8.1. But my HDD, in MBR runs win 7 x64 perfectly. Now, I am trying to install win 8.1, but the setup says that it cannot be done because the HDD is in MBR. Now, I have lots of data on the drive and do not want to format it, delete all partions, convert to GPT, and then insatall 8.1. Any Help?
 

My Computer My Computer

At a glance

Windows 7 Ultimate SP1 x64AMD FX 8320 @ 3.5Ghz8 GB @1600 MhzZotac GeForce 750Ti OC
Computer type
PC/Desktop
Computer Manufacturer/Model Number
Custom Build
OS
Windows 7 Ultimate SP1 x64
CPU
AMD FX 8320 @ 3.5Ghz
Motherboard
Gigabyte GA-990XA-UD3
Memory
8 GB @1600 Mhz
Graphics Card(s)
Zotac GeForce 750Ti OC
Screen Resolution
1920x1080 ; 1440x900
Hard Drives
Segate Barracuda 1TB
Segate 160GB
PSU
Antec 650W
Case
Antec v1
Cooling
Cooler Master SickleflowX x5
Browser
Chrome
You should have a BIOS setting for CSM, Compatibility, or Legacy BIOS to enable so that you can use an MBR disk for booting OS and/or data. If you're unsure post back the settings choices for these. Pictures will help. http://www.sevenforums.com/tutorials/9733-screenshots-files-upload-post-seven-forums.html

Then be sure to boot the installation media as a legacy and not UEFI device, from the BIOS boot menu or Boot Priority order.

If you want to try to adapt the OS on the HD to run on the new hardware you can try to http://www.sevenforums.com/tutorials/292068-make-windows-7-bootable-after-motherboard-swap.html

In either case it may require confirming the Partition Marked Active is the 100mb System Reserved (preferred if you have it) or C, then running http://www.sevenforums.com/tutorials/105541-startup-repair-run-3-separate-times.html to get it started.

Otherwise you can reinstall to the OS partition if you have your data separated to another partition. But it's always risky to not have data backed up. You can back up 15gb for each Windows Live ID to the cloud with MS OneDrive. Here is also a way to http://www.sevenforums.com/backup-r...re-your-files-cloud-skydrive.html#post2269172
 
@gregrocker
First of all, thank you very much for helping me out.
I found the"legacy" BIOS setting in the 'features' section of my BIOS, and after reformatting the USB drive to NTFS, was able to install Windows 8.1 successfully.
I already have all my data backed up to an external HDD, but I did not want the hassle of restoring all that amounts of data back.
Anyway, thanks, I appreciate your help very much.
 

My Computer My Computer

At a glance

Windows 7 Ultimate SP1 x64AMD FX 8320 @ 3.5Ghz8 GB @1600 MhzZotac GeForce 750Ti OC
Computer type
PC/Desktop
Computer Manufacturer/Model Number
Custom Build
OS
Windows 7 Ultimate SP1 x64
CPU
AMD FX 8320 @ 3.5Ghz
Motherboard
Gigabyte GA-990XA-UD3
Memory
8 GB @1600 Mhz
Graphics Card(s)
Zotac GeForce 750Ti OC
Screen Resolution
1920x1080 ; 1440x900
Hard Drives
Segate Barracuda 1TB
Segate 160GB
PSU
Antec 650W
Case
Antec v1
Cooling
Cooler Master SickleflowX x5
Browser
Chrome
Back
Top