Windows 7 won't start after changing permissions (black screen) [Closed]

Registration date
Wednesday January 22, 2014
Last seen
January 24, 2014
 Finn -
After changing some permissions I cannot get into my computer and can't even boot into safe mode. I can only boot with Windows 7 Recovery CD. Startup repair won't fix anything but I can use command prompt (cmd) and get into regedit.

I have been able to change the following key value as advised here: But for some reasons the settings won't apply and I would still get black screen with moving cursor. Ctrl+Alt+Del won't work.

Mouse cursor is visible and movable. I have read that it is due to some file permissions. I have already took ownership and granted full control to Administrators and SYSTEM.

When I use Recovery CD there is system restore that won't work, Startup repair won't work either, I can only use command prompt that starts with X:\Sources>.

The command prompt is entitled Administrator: X:\windows\system32\cmd.exe
My OS is intalled on C: drive, however. The drive is active and partitions are OK. Should I somehow change that X:?

Any help would be much appreciated.

2 replies

Registration date
Wednesday October 8, 2008
Last seen
June 15, 2019
The recovery CD installs striped-down version of Windows on a "virtual drive" which it names 'X".

I suspect you will need to re-install Windows.

Good Luck
I have exactly the same problem on Windows 7, which was also caused by changing security permissions. Ctrl+alt+del, startup repair, sfc scannow, and chkdsk aren't helping so far.

I don't want to do a fresh Windows 7 installation.

Is there a way to restore security permissions to their original state?

Is there a way to do a repair install of Windows 7 without booting up the computer?

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