PC Freezing before Logon Screen

[Zoom7000]

My PC is setup to use the fast user switching logon screen. Up until lately it was working absolutely fine. However, in the last few days I have noticed that after a cold boot, the computer boots into Windows and then I get nothing but a mouse pointer in the middle of the screen. The PC still appears to be responding and hasn't exactly crashed, but I don't get anything, no logon screen at all, just the blue background. Ctrl + Alt + Del doesn't do anything either and I have to use the reset button on the machine. It then loads up fine without an issue.

So does anyone know what could be causing the initial failure?

Zoom7000

[cluberti]

NOTE - this assumes you have a PS/2 keyboard (USB will not work), and you can boot into Safe Mode:

1. Boot into safe mode w/networking (hopefully this will work) and fire up regedit.exe

2. Create or set the following registry value:

Key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\i8042prt\Parameters

Value: CrashOnCtrlScroll

Type: REG_DWORD

Data: 1

3. Right-Click on the "My Computer" icon on the desktop and select "Properties"; this will open the "System Properties" window. Go to the "Advanced" tab and click "Performance Options". Click "Change" under "Virtual Memory". Set the pagefile to be located on the partition where the OS is installed, and set it to be equal to Physical RAM + 50 MB.

4. Also in the "System Properties" window, click on the "Advanced" tab, then click "Startup and Recovery". Make sure "Complete Memory Dump" is selected (see 4a if this is not in the list). You can change the location of the memory dump file to a different local partition if you do not have enough room on the partition where the OS is installed.

4a. If the "Complete Memory Dump" option in step 4 is not available, you will need to manually set this registry value:

Key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\CrashControl

Value: CrashDumpEnabled

Type: REG_DWORD

Value: 1

5. You will need to reboot the computer for these changes to take effect.

6. The next time that the computer hangs, hold down the RIGHT CTRL key and press the SCROLL LOCK key twice to cause the computer to bugcheck and create the memory.dmp file. Boot back into safe mode w/networking to get the %windir%\memory.dmp file off of the machine for review.

This will give us a complete memory dump of the machine in it's "hung" state, and we should be able to figure this out. I can give you FTP instructions offline once you've gotten the memory.dmp file.

NOTE also that if you do press the keyboard combination in step 6 and the machine does not bugcheck, it's likely a hardware issue.

[Zoom7000]

Thanks for that mate, I will give it a roll tonight or tomorrow.

[Zoom7000]

I think the problem appears to have been resolved. Presumably the freezing was being caused by Alcohol120%. I had just downloaded what was the updated version, and once I had uninstalled it, it has loaded up fine ever since.

Thanks for your help anyway cluberti.

[FthrJACK]

Probably the system driver for the virtual CD/DVD.... at a guess. Try an older version of 120% and see?