Windows 7 boots to black screen with cursor before login screen after changing permissions on the system32 directory

Question

Original Title: Windows 7 boots to black screen with cursor before login screen, nothing works

I turned my computer on yesterday to find that, after the Windows loading screen, everything went black. The cursor is there and will move around, but right clicking does nothing, Ctrl-Alt-Del does nothing, safe mode does nothing, system restore does nothing, startup repair does nothing, sticky keys does nothing, absolutely nothing on earth will get me to the login screen. I've tried every solution on every website I could find and none of them did anything.

If it helps, I was tooling around with ownership of the System32 file before this started and, well aware of the inherent risks, I transferred ownership of the folder to myself so I could replace ONE DLL with a newer version. The name of the DLL is dwmapi.dll. Then, after turning off my computer, everything went to black. What should I do?

Answer 1

There are several ways to replace a file in the System32 folder. Messing around with NTFS permissions is not one of them. You could now try this:

1. Keep tapping F8 at boot time in order to boot into Repair Mode.
2. Open a Command Prompt.
3. Identify the drive letter for your System drive. It is usually C: but it could be D: or E:. It won't be X:. I will call it Q: for the purpose of this exercise.
4. Type the following commands and press Enter after each. Make sure to type them accurately - do not take any liberties!

path  %path%;Q:\Windows\System32

cacls  Q:\Windows\System32  /E  /T  /C  /G everyone:F

(this command will probably take a long time to run) 5. Reboot normally. If your problem was caused by inappropriate permissions then Windows should now work. 6. Click Start. 7. Type the three letters cmd into the Search box. 8. Press Ctrl+Shift+Enter 9. Click "Run as Administrator". 10. Type the following commands and press Enter after each of them:

cacls  C:\Windows\System32  /E  /T  /C  /G  System:F  Administrators:R

cacls  C:\Windows\System32  /E  /T  /C  /G  everyone:R

Answer 2

Hi Johneliasen,

Sorry for delayed response.

What is the exact make and model of the computer?

The black screen issue that you’re facing could be related to drivers and could be resolved by updating the display drivers. Without the correct driver, the hardware or device that you want to use won't work properly.

I suggest you to follow the article by Sharath Srinivasa replied on April 5, 2012 mentioned below.

http://answers.microsoft.com/en-us/windows/forum/windows\_7-system/windows-7-boots-to-an-unresponsive-black-screen/88cab12b-6977-4d47-bb0e-f6b6c7642e7e

Hope the information helps.

Answer 3

I just spent about 30 hours hacking this problem and here is what I found.

First this was a result of a computer upgrading to windows 10 without asking.

I did the roll back to windows 7 and which then resulted in the Black Screen with a Cursor.

The only response I could get was if you held the Windows Key and U or P

for the handicap feature or dual Monitor setting.. No Logon Screen, No Ctrl-Alt-Del

First I drive Imaged the Hard drive to a second drive so I was free to experiment. I tried just about every suggestion I could find on Google and Microsoft ... None of which worked. It had nothing to do with permissions or drivers.

Safe Mode, command prompt did not work etc, restore to previous did not work(looks like win10 deleted all my old restore points... Thanks MS)

It was the registry that was screwed up and causing the problems.

(I used a second computer and usb HD Caddy to mount my hard drive in a working computer)

Unfortunately the backup of the registry was no good either, windows 10 must have found a way to mess it up as well. I had an older backup of the the registry files which I copied into place at

(X: is drive letter of your Hard Drive your Trying to fix)

X:\windows\system32\config

there should be a backup in

X:\windows\system32\config\regback

(files you need to restore are

default

sam

security

software

system

) I did not test to see which file was the one the problem was in I copied all 5

I can't stress how important it is to make backups of these files, (I used to do this always in XP do to various problems that could happen and even more so back in win98)  You are almost always forced to reload windows if you can't fix these files.

A note to all of you out there, make a backup of these files NOW BEFORE WIN10 Upgrade Bites your butt.

Answer 4

Hi,

I'm also facing the similar kind of problem for last 4 days.  I use a Lenovo Thinkpad T410 with Windows 7 Professional OS. What I did was I pressed the power button to turn the computer off when it was on, as I was in a hurry. 

Later on, when I tried to start the computer , it asked to the startup repair. When I started the repair, it ran for about 2-3 hours , then after reboot it was a black screen with just the cursor on.

I tried to do many troubleshooting but all gone in vein.

I even tried to check the registry value of Shell  under( HKLM/Software/Microsoft/Windows NT/Current Version/Win logon)  after accessing the registry from recovery option but after restarting the computer again the value changed to another value. I even tried to delete the existing Shell Key and created another key but nothing worked.

I don't have any restore point created and no recovery image saved on my Hard Disk.

I did even ran Memory Diagnostic tool, it ran the diagnostic but didn't find any problem.

Anyones, with any suggestion or solution tips would be highly appreciated.

Thanks,

Anirban

Answer 5

icacls C:\* /Grant Everyone:F /setintegritylevel:OI /inheritance:e

After entering this command I was able to log in successfully.