I have broken W 10 by trying to take ownership of C:\ please help!

Phil0sophy said:

Ok I have severely screwed up now, followed the guide for windows clean install and created a a boot USB, deleted the two partitions on my main drive (left my other two hard drives as they have the backup on them) and it's now telling me windows can't be installed on this drive.
"The selected disk has an MBR partition table. On EFI systems windows can only be installed to GPT disks"
I have already deleted the partitions, what am I going to do?

Thread Necro!

I had this same issue while reinstalling Windows 10. I got around it by using something like EaseUS Partition Master, GParted, or Minitool as a bootable partition on a USB drive or on a disc to convert the existing GPT partitions to MBR until after Windows is installed. Then, if you wish, you can convert the partitions back to GPT.

Hi are u still up there? I'm having the same problem as yours, And I don't know exactly what to do, could you guide me?

pepanee said:

Try this out:

a) Open Windows Settings -> Update & Security -> Recovery
b) Press the Restart now button under Advanced startup
c) Press the Troubleshoot -> Advanced options -> Startup Settings -> Restart buttons.
d) Select: 6) Enable Safe Mode with Command Prompt
e) Once the Command Prompt is displayed, type:
sfc /scannow
and press the Enter key
f) This process will take some time
g) Once that process completes, press Control+Alt+Delete then press the Power button -> Restart

Thsnkyou so much for your response, but I decided to just reset my pc , reasoning that I don't have any personal information files there, Just resetted this pc to make it go back just like the original state.

pepanee said:

Okay that works too. Hope you got it all working again =)

I also resetted it to delete files and clean drive. It cause me fail start, so I reinstalled the windows 10

hello, I registered into this forum just to share this :
I had this same problem and found the solution :
go to prompt command in safe mode at computer start, (pushing F4 for me on windows 8.1, then push F8 to get to the reparation menu, and then select to access the "prompt command in safe mode")...
go to your drive that contains windows (care to find it, it may not be c:\, verify content of drive by doing for example "cd e:" -return- then "dir" -return-)

once you find the good drive, type "ICACLS * /T /Q /C /RESET" and return; it will take a while, be patient;
this will reset all permissions of every files in every directories of this drive to default and save your day.
kthxbye

philc43 said:

If you have setup System Restore Points then the simplest approach is to restore to a point in time before you made the changes to your C:\ drive.

System Restore Windows 10

Yeah, I tried a system restore but it does not restore ownership of folders to default.

QoHeLeTh said:

Yeah, I tried a system restore but it does not restore ownership of folders to default.

To expand on post #28 which is worth trying before a complete Repair Install of Win10 -
How to reset NTFS permissions with ICACLS | The Solving