Fixing a Windows UEFI Bootloader installation

[destrekor]

So - I thought I had all pertinent drives unplugged when I did a fresh install of Windows 8.1 last month. Felt like since I was already that far, I would upgrade to a true UEFI bootloader since I already use one for OS X on the same system (and am hoping it makes it easier to select both from the same bootloader, with Clover taking the lead in UEFI/BIOS boot order - or even the other way if at all possible, though I doubt it).

However, I left one other drive connected, and... it appears that the boot loader must reside on that drive. Only a single partition is listed for what should be the system drive, when there should be four partitions in total.

If I do a upgrade to Windows 10, disconnect all drives, and shrink the C: partition and make the other partitions that should be there, would the installer see this and fix the bootloader? Or, if even doing that, if I use the Recovery console to "fix" the bootloader, would it install what it needs?


No idea if this is related, but something else was incredibly weird: When I went to use Windows' system image backup utility, it automatically included an entirely different disk as a "system" drive, and I couldn't un-check it. It's just a standard MBR disk for storage, no installation on it.

Is it possibly being OneDrive is pointed to that storage partition? Or in general have included some directories there in my Libraries? Both my music and additional document storage is there, I don't want it taking up SSD space.

I don't think I had previously included those directories as part of the system libraries - I liked that it made things a touch easier to see the big picture when pulling up documents.

 

[Puffnstuff]

When you do a clean install of 10 make sure the system drive is the only drive attached besides the dvd/bd for the os installation if using optical. In the install menu when it shows you the drive delete all partitions leaving only unallocated space then click on new and let windows correct your partitions creating the efi, recovery and ntfs sections on its own. Once it has finished you should have a normal uefi installation provided that your installation media is set to uefi mode (uefi dvd, uefi thumb drive, etc.) which will install windows in uefi mode.

 

[Ketchup]

See if this helps:

http://www.mysysadmintips.com/windows/clients/236-move-windows-7-bootloader-to-another-disk

 

[destrekor]

When you do a clean install of 10 make sure the system drive is the only drive attached besides the dvd/bd for the os installation if using optical. In the install menu when it shows you the drive delete all partitions leaving only unallocated space then click on new and let windows correct your partitions creating the efi, recovery and ntfs sections on its own. Once it has finished you should have a normal uefi installation provided that your installation media is set to uefi mode (uefi dvd, uefi thumb drive, etc.) which will install windows in uefi mode.

I'm not doing a clean install.

I just did one a month ago - my system is clean. I'm not going through that pain in the ass again. I'm not even at where my system was in the first place.

I also know how to install UEFI. Last time I just didn't disconnect all drives. I let Windows handle the partitioning and it apparently decided it didn't care to follow instructions, utilized another UEFI partition elsewhere and appears to not have created any of the other partitions it was supposed to create.

 

[destrekor]

See if this helps:

http://www.mysysadmintips.com/windows/clients/236-move-windows-7-bootloader-to-another-disk

I think I've read that that tool only works for MBR disks with standard bootloader, not GPT disks with UEFI.

 

[kbirger]

If you get into a situation where you don't feel like reinstalling, you can always do some trickery to convert an existing install to UEFI/GPT. I tried this with success:

http://social.technet.microsoft.com...erting-windows-bios-installation-to-uefi.aspx

Caveats:
1) Make sure you have plenty of free space
2) You may need to run something like Perfect Disk to move the MFT to the beginning of the drive, otherwise you will be unable to shrink your disk to make space for the new partitions. (You can google this to find whichever software/method you prefer). Additional caution... gptgen will fail and you will be left in a non-bootable state if you do not do this first. (Happened to me)

 

[destrekor]

If you get into a situation where you don't feel like reinstalling, you can always do some trickery to convert an existing install to UEFI/GPT. I tried this with success:

http://social.technet.microsoft.com...erting-windows-bios-installation-to-uefi.aspx

Caveats:
1) Make sure you have plenty of free space
2) You may need to run something like Perfect Disk to move the MFT to the beginning of the drive, otherwise you will be unable to shrink your disk to make space for the new partitions. (You can google this to find whichever software/method you prefer). Additional caution... gptgen will fail and you will be left in a non-bootable state if you do not do this first. (Happened to me)

This is already a GPT/UEFI install.

 

[Puffnstuff]

You could always try creating a new efi partition on the existing drive and then point the bios to the bootloader without the other drive attached so it is the only one present. If it will boot then once the other drive is attached remove the efi partition from it after backing all data on it up because I tried it with one of mine just last week and it wiped the entire drive out.

 

[destrekor]

You could always try creating a new efi partition on the existing drive and then point the bios to the bootloader without the other drive attached so it is the only one present. If it will boot then once the other drive is attached remove the efi partition from it after backing all data on it up because I tried it with one of mine just last week and it wiped the entire drive out.

You could also just completely blank out the EFI partition but not remove it.

I have a few different EFI partitions across multiple drives, because two are Clover EFI partitions, one for the main system, one is a whole-drive backup to include a functional bootloader.

Clover installs, as they are manual, handle that perfectly without any need to juggle disk connections. Windows, however, appears to loathe the presence of multiple bootloaders and just takes over.

I still need to dig into the EFI partitions to check out the file structure, see if Windows co-opted and/or overwrote one of the Clover partitions.