Raw filesystem on EFI partition, Windows 8.1 can't boot

[rejelepindre]

Hi everyone.
My CPU recently blew up. I had it changed but Windows can't boot since. I get error 0xc0000001 with \EFI\Microsoft\Boot\BCD missing or corrupted. From recovery USB, startup repair and bootrec /rebuildbcd failed. Then, trying to use bcdedit, I realized that diskpart lists my EFI boot volume as RAW and I can't cd to it. So I think I may have a bigger problem than a corrupted BCD file.

I use a dual boot with Xubuntu, and the EFI boot partition shows as fat32 in Gparted. I may also have messed up the bootcat.cache file, but I think it is ok. My hard disk is hybrid SSD.

So my questions are:
1) Is it possible that while blowing up, my CPU somehow messed up my hard disk file systems?

2) Is there a way to make Windows see my EFI boot volume as FAT32 again?

3) Have I got it all wrong and there is an other way to deal with it?

Thanks

Seb

 

[MCPlayer18]

What do you mean by "Blew Up"? Also, if it was very close to your hard drive, then yes. The heat may have messed the hard drive up. You can always get a new hard drive AND you have to make sure that you everything is compatible.

 

[rejelepindre]

Sorry I should have used other words than "blew up". It is not like the CPU exploded ... it just stopped working. The computer crashed suddenly while I was watching a video, and then the computer did not boot anymore.

The hard drive seems to work properly. Now that the CPU was changed, I can use my linux OS and even access all the files on my Windows partition from it. It is just that the EFI (SYSTEM_DRV) and LRS_EPS volumes appear as RAW. I am hence unable to access them or use them to boot Windows. Strangely enough, my GRUB bootloader (grubx64.efi) is also on the EFI partition and is accessed while booting linux.

 

[MCPlayer18]

How big is the partion? (For windows)

 

[rejelepindre]

The Windows partition is 213 G, as I wanted 200 G on linux and this is what was left. I attach a screen shot of my drive partitions on GParted from linux.


The partition with label SYSTEM_DRV is the boot partition and is the one that appear as RAW in Windows.

Thank you. Sorry for the delayed answer, I'm in China right now and it was night.

 

[MCPlayer18]

This may help.

Dual Boot - Delete a OS - Windows 7 Help Forums

If you want to either re-install windows or re-install linux. Make sure to use you cd-disc for windows/linux (however you installed it)

 

[SIW2]

Whereabouts in China are you?

Have you tried a bootable windows based (winpe) partition manager ?

 

[rejelepindre]

I'm in Wuhan, province of Hubei. It is very hot right now!

Thank you guys for your advice. Sadly, I can't use the dual boot tutorial from Windows 7 forum, as it uses EasyBCD, which they say should not be used with UEFI. WinPE looks great, but if I understood correctly it is not free. So I would rather reinstall everthing from scratch with my free Windows recovery disc.

Anyway, following links in the websites you pointed out led me to testdisk TestDisk Step By Step - CGSecurity which I thought might help me clean my partitions. The output of testdisk suggests me that my disk partitions are REALLY messed up. It shows like if I had 50 partitions, with like 15 copies or my boot partition.


I don't know how this happened or if it was a result of my broken CPU. So i'll just go ahead and try to format and reinstall everything from scratch with my recovery disc. Sorry, I know it is a disapointing workaround.

 

[mysery126]

I am afraid you have to reinstall windows if you have not taken backups

 

[KYHI]

Boot into windows 8.1 setup media
when on the "install" screen press Shift+F10 to bring up a command prompt
Type the following>

diskpart
list disk
select disk # ( # = disk number for the disk with the efi partition)
list partition
select partition # (# = efi partition)
create partition efi size=260
format quick fs=fat32 label="SYSTEM"
assign letter="S"
exit

assuming C is still the drive letter assigned to your windows 8.1 partition
type>

C:\Windows\System32\bcdboot C:\Windows

 

[rejelepindre]

Thank you for your answer KYHI, the solution you propose looks very neat.

However, I can not really try it as I already formatted all my disk and reinstalled from scratch, which worked very well. Your solution would have saved me from reinstalling all my software, but I am now happy to be sure that all my disk partitions are ok, not just the efi one.

Also, at the time, I did not feel very safe to reformat the efi partition alone, as I thought it would break by Ubuntu boot. I now realize that simply using a linux boot-repair usbkey just after your solution would have most likely solved all my problems.

 

[hydranix]

That's a shame... the efi partition is easy to fix, hardly worth formatting the entire disk...

 

[mintar]

In case somebody finds this post in the future (like I just did): I was in the same situation as rejelepindre and managed to make it work with hydranix's instructions, with a couple of small changes:

1. Back up the contents of the EFI partition (on Linux)

2. I had to delete the old partition before creating a new one:

diskpart
list disk
select disk # ( # = disk number for the disk with the efi partition)
list partition
select partition # (# = efi partition)
delete partition override
create partition efi size=260
format quick fs=fat32 label="SYSTEM"
assign letter="S"
exit

3. Afterwards, copy the old EFI contents back to the new partition (using a Linux live USB stick)

4. Run boot-repair ( https://help.ubuntu.com/community/Boot-Repair ) to fix Linux/Windows dual boot.

 

[Kwc]

Hi, I encountered a similar problem where my efi partition has become raw and i'm trying out the instruction by mintar. However when i try to format the partition to fat32, it says that diskpart encountered an error: the parameter is incorrect.
May I know how should I solve this? Thanks