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Yesterday I tried to install a driver for my graphics card (Geforce 8400 GS) from the official Nvidia site.

During the installation my PC crashed.

When I restarted it I had no usable monitor signal: Only black stripes and stripes with colorful pixels.

Now here's the wierd part: After rebooting again I heard the normal Windows Vista start up sound and I was able to make out my desktop backround and the mouse cursor in the pixelated mess and I was able to shut down the PC normally. (I also checked that it is not a monitor problem by pluging in a different monior.)

Since I believe the failed driver installation screwed something up, I tried to enter safe mode or restore previous settings, but the screen signal is so bad that I can't see any text and can't select the right options.

TL;dr:Graphics card bricked, think it's a driver problem. Is it possible to restore system defaults witout a usable monitor signal?

I'm at my wits end and would really appreciate any help!

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2 Answers 2

Reboot the computer, after the bios POST has gone, press F8 before the windows loading screen comes up, this should bring up a menu, from the menu select safe mode. When safe mode opens go to device manager and to your video card and open up the properties, then go to rollback driver.

Another option is to go into safe mode and run system restore this will also roll everything back to before you installed the driver.

Either of the above should work, you should be able to see fine, as when you load safe mode it loads the default vga driver so will ignore your new driver.

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Thanks for your answer! But even the BIOS screen is screwed and I can't see which options I'm selecting. –  Emerson Feb 3 '12 at 14:13
    
Hmm that's not a good sign, if that's the case, its more a card issue, as the drivers for windows have no effect on the bios screen, that's BEFORE windows loads. Did you do a firmware upgrade or a driver upgrade ?. –  Iain Simpson Feb 3 '12 at 14:22
1  
It was a driver (GeForce 285.62 Driver). So you are saying the firmware is in effect before Windows starts and what I observe points to a hardware issue? –  Emerson Feb 3 '12 at 14:39
    
Yes, to prove this point, if you discconect your hard drive, you pc will still bios POST, it just wont go any further. If the bios POST is all wavy its a hardware or firmware issue, as this is before the driver software has even been loaded. –  Iain Simpson Feb 3 '12 at 14:58

If you have no good BIOS screen I would agree that it is almost certainly hardware. I want to post an answer that won't fix yours if that is the case, but because I spent 6 hours on an identical problem that was a driver that simply defied all fixes (BIOS and safe boot worked fine).

When diagnosing a driver problem, one of the first things I do is boot from an Ubuntu LiveCD to test hardware. In my case it booted and worked fine so now I am leaning heavily toward driver. I boot in safe mode and try all the typical fixes, new driver, old driver, roll back, etc. I barely notice (because I'm impatient and don't read closely enough) that at some point the driver install is seemingly completing but with a message "system not modified". So I have a screwed up system and something is blocking the ability to fix it normally.

In this case it was a registry permission error that was solved by a microsoft tool called SubInACL.exe which was used with a command file that looked like the following.

Future reader: If you find this and have a simiilar problem, don't just run off and try it. Do the research, read the blog posts, google "nvidea subinacl reset permission" and make sure you understand what is going on. I have run this on several systems with update and install errors with no ill effect, but caveat emptor.

    @echo off
title Resetting ACLs...

echo.
echo Determine whether we are on an 32 or 64 bit machine
echo.

if "%PROCESSOR_ARCHITECTURE%"=="x86" if "%PROCESSOR_ARCHITEW6432%"=="" goto x86

set ProgramFilesPath=%ProgramFiles(x86)%

goto startResetting

:x86

set ProgramFilesPath=%ProgramFiles%

:startResetting

echo.
cd /d "%ProgramFilesPath%\Windows Resource Kits\Tools"
echo. 
echo Resetting ACLs...
echo (this may take several minutes to complete)
echo. 
echo IMPORTANT NOTE: For this script to run correctly, you must change
echo the values named YOURUSERNAME to be the Windows user account that
echo you are logged in with.
echo.
echo ==========================================================================
echo. 
echo. 
subinacl /subkeyreg HKEY_CURRENT_USER /grant=administrators=f /grant=system=f /grant=restricted=r /grant=man=f /setowner=administrators > %temp%\subinacl_output.txt
echo. 
echo. 
subinacl /keyreg HKEY_CURRENT_USER /grant=administrators=f /grant=system=f /grant=restricted=r /grant=man=f /setowner=administrators >> %temp%\subinacl_output.txt
echo. 
echo. 
subinacl /subkeyreg HKEY_LOCAL_MACHINE /grant=administrators=f /grant=system=f /grant=users=r /grant=everyone=r /grant=restricted=r /setowner=administrators >> %temp%\subinacl_output.txt
echo. 
echo. 
subinacl /keyreg HKEY_LOCAL_MACHINE /grant=administrators=f /grant=system=f /grant=users=r /grant=everyone=r /grant=restricted=r /setowner=administrators >> %temp%\subinacl_output.txt
echo. 
echo. 
subinacl /subkeyreg HKEY_CLASSES_ROOT /grant=administrators=f /grant=system=f /grant=users=r /setowner=administrators >> %temp%\subinacl_output.txt
echo. 
echo. 
subinacl /keyreg HKEY_CLASSES_ROOT /grant=administrators=f /grant=system=f /grant=users=r /setowner=administrators >> %temp%\subinacl_output.txt
echo. 
echo. 
echo System Drive...
subinacl /subdirectories %ProgramFilesPath%\ /grant=administrators=f /grant=system=f /grant=users=e >> %temp%\subinacl_output.txt
echo. 
echo. 
echo Windows Directory...
subinacl /subdirectories %windir%\ /grant=administrators=f /grant=system=f /grant=users=e >> %temp%\subinacl_output.txt
echo. 
echo. 
echo ==========================================================================
echo. 
echo FINISHED.
echo. 
echo Press any key to exit . . .
pause >NUL
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