UEFI Partition Wiped After Windows 7 Installation

Hello all. My first post on these forums. Hope I don't break any rules in it
I'll try to be short and clear in describing my problem, but please bare with me here as it's not the simplest of issues (not to me anyway).
I got a (at the time new) MSi laptop several months back with just a regular Windows 8 Core x64 on it and a UEFI boot system (or whatever is the name for "BIOSs"). At some point I had problems with the settings - I couldn't open any of my computer's settings - and I researched long and hard to no avail. So I installed Windows 7 32-bit (the only disk I had). Now, I'm trying to upgrade to Windows 8.1 Pro. I noticed that after the installation of 8.1 Pro my system was still running in 32-bit, so I made a bootable USB stick with the retail version of Windows 8 Core with no key just to get the system back to x64. It worked just fine. I cannot, however, boot in UEFI mode. I believe the partition got wiped somewhere in the Windows 7 installation. Whenever I enter UEFI by pressing the DEL button (I cannot see the UEFI firmware settings tile under the Troubleshoot option) I see the boot mode is LEGACY and when I change it to UEFI, save and reset, it doesn't boot, giving me a "No media found" error. I don't care about my settings/files as long as I get UEFI back with Windows 8.1 Pro running.
I googled long enough to know I'm not going anywhere if I don't ask someone with expertise on this matter.
My next attempt would be to try and install 8.1 Pro from USB stick, wipe all the partitions and hope the installer will create new ones. The reason this would work when it didn't before is because I had the OS running in x86 not x64 (which UEFI doesn't support). So maybe now that the system is back to x64 the Windows installation will restore the UEFI back to its original state.
Thanks in advance for any solutions :thumb:

Yes that is correct, when you load a different OS on the hard drive. All previous partitions are wiped off of the hard drive. Only way to get it back, is to reinstall Windows 8.x.x.

SumCreepyDude said:

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My next attempt would be to try and install 8.1 Pro from USB stick, wipe all the partitions and hope the installer will create new ones.

Click to expand...

Absolutely that would work.

Hi there

1) Disable protected boot -- your system can still boot UEFI -- there's confusion on the Forums -- protected boot (requires UEFI) - windows keys are embedded in the BIOS and you can't boot legacy or other OS'es - even a standard Windows recovery disk. Disabling protected boot allows legacy boot (as well as UEFI boots). UEFI does NOT require protected boot.

2) convert HDD to GPT - a requirement for UEFI boot.

3) Now perform Windows recovery from your Windows CD - or re-install -- this will install the UEFI version without any more problems - you don't need to do anything unless the boot menu gives you a choice between the UEFI and non UEFI install.

Cheers
jimbo

edit:

How to download and clean install Windows 8.1 -> link

Here is info about UEFI Boot Mode (installing using the GPT partition style) and Legacy BIOS Boot Mode (installing using the MBR partition style): link

SumCreepyDude said:

I got a (at the time new) MSi laptop several months back with just a regular Windows 8 Core x64 on it and a UEFI boot system (or whatever is the name for "BIOSs")

My next attempt would be to try and install 8.1 Pro from USB stick, wipe all the partitions and hope the installer will create new ones.

Click to expand...

I have a Lenovo laptop with preinstalled Windows 8 (core) x64, but then I have made a clean installation of Windows 8.1 Pro x64.

1. Create a Windows 8.1 64-bit USB flash drive.

UEFI Bootable USB Flash Drive - Create in Windows

To create a bootable UEFI USB flash drive using Rufus.
- Connect your USB flash drive.
- Click/tap on the browse icon and select your Windows 8.1 64-bit ISO image file.
- Under Partition scheme and target system type, select GPT partition scheme for UEFI Computer
- Under File system, select FAT32
- Click/tap on Start.

2. You don't need to change the default UEFI firmware (BIOS) settings.

3. Install Windows 8.1 Pro 64-bit

http://www.eightforums.com/tutorial...e-firmware-interface-install-windows-8-a.html

4. Press whatever key (ex: F11) it shows to boot to your motherboard's boot menu, and select to boot from the listed UEFI DVD or UEFI USB. (see screenshot below)

5. Do steps 2 to 7 in the tutorial at the link below, and return.

Clean Install - Windows 8​

6. Delete all partitions/volumes on the disk # (ex: Disk 0) that you want to install Windows 8 as UEFI on until that disk # shows as unallocated space. (see screenshot below)

7. When you are finished, click/tap on New, Apply (for full size of disk), and OK. (see screenshot above)

8. You will notice that the disk has now been formatted as GPT with 4 partitions. Select the "Primary" partition 4, and click/tap on Next. (see screenshot below)

Click to expand...

I recently had to delete all all partition including the recovery partition on uefi laptop to install win7 ,and I had used Refus to create the thumb drive install for uefi ,it didn't work ,I could find no way around it but delete all partitions ,for me it didn't matter to lose all the partitions

genet said:

SumCreepyDude said:

I got a (at the time new) MSi laptop several months back with just a regular Windows 8 Core x64 on it and a UEFI boot system (or whatever is the name for "BIOSs")

My next attempt would be to try and install 8.1 Pro from USB stick, wipe all the partitions and hope the installer will create new ones.

Click to expand...

I have a Lenovo laptop with preinstalled Windows 8 (core) x64, but then I have made a clean installation of Windows 8.1 Pro x64.

1. Create a Windows 8.1 64-bit USB flash drive.

UEFI Bootable USB Flash Drive - Create in Windows

To create a bootable UEFI USB flash drive using Rufus.
- Connect your USB flash drive.
- Click/tap on the browse icon and select your Windows 8.1 64-bit ISO image file.
- Under Partition scheme and target system type, select GPT partition scheme for UEFI Computer
- Under File system, select FAT32
- Click/tap on Start.

2. You don't need to change the default UEFI firmware (BIOS) settings.

3. Install Windows 8.1 Pro 64-bit

edit: Windows 8.1 installer (when you install Windows 8.1 from DVD/USB) does not accept UEFI firmware (BIOS) embedded Windows 8 product key and will not automatically install Windows 8.1 (core), so you can enter your Windows 8.1 Pro product key.

http://www.eightforums.com/tutorial...e-firmware-interface-install-windows-8-a.html

4. Press whatever key (ex: F11) it shows to boot to your motherboard's boot menu, and select to boot from the listed UEFI DVD or UEFI USB. (see screenshot below)

5. Do steps 2 to 7 in the tutorial at the link below, and return.

Clean Install - Windows 8​

6. Delete all partitions/volumes on the disk # (ex: Disk 0) that you want to install Windows 8 as UEFI on until that disk # shows as unallocated space. (see screenshot below)

7. When you are finished, click/tap on New, Apply (for full size of disk), and OK. (see screenshot above)

8. You will notice that the disk has now been formatted as GPT with 4 partitions. Select the "Primary" partition 4, and click/tap on Next. (see screenshot below)

Click to expand...

​

Click to expand...

If you don't install in UEFI Mode you don't get the EFI partition. That partition should be created automatically if you do the install correctly. And your BIOS is set correctly.