Hi everyone,
I have recently been having some problems with avast anti virus causing windows vista to hang so in order to find out what could be causing I was told to edit the registry so that when it hanged I could press Ctrl and Scroll lock and it would force a BSOD to create crash dump file.

First time I tried it was just a test as I was unsure if it would work. Due to my lack of knowledge at the time I thought you needed to then delete the old DMP file. I simply renamed it and set up the system so it would hang and then I could forced the BSOD again, but this time the BSOD just dud nothing with no mention about the percentage complete of the crash dump file. My hard drive activity light just stayed on red with no sound of the hard drive actually running.

I decide to rename the DMP file back to what it was but now no matter what state the computer is in either working fine or hanging, the BSOD just does nothing. No dump file is ever created and the computer never seems to restart.

I have checked my start-up and recovery settings and the “write system log” and “automatically restart” box is ticked and so is “overwrite existing file” and the dump file goes here: %SystemRoot%\MEMORY.DMP

Does anyone have any idea of what could be going wrong?

Thanks in advance

Is the minimum and maximum size of your page file set to be at least RAM+50MB? Also, is your paging file on the boot volume (the same volume as the \windows folder)?

Thanks cluberti for the suggestions, here is some more information.
Well I went to System properties -> Advanced tab -> Clicked on the settings button under the performance label -> The "Virtual memory" window opened and "Automatically manage paging file size for all drives" is ticked. In the "Paging file size for each drive" only my C: drive is listed which is my hard disk which seems correct since that is the drive that has windows vista installed. The only other drives I have is A: (Floppy) and D: (DVD). The paging file size column says "System managed" although further down the window in "Total paging file size for all drives" it has this:
Minimum allowed: 16 MB
Recommended: 1533 MB
Currently allocated: 1322 MB
I currently have 1GB of RAM installed.

Hope that helps in solving the problem.

It does - you need to set the paging file size manually to 1533MB for both min and max values, and make sure the dump is set to "Complete". Once you've done this, reboot and your keyboard dump should work. The only other thing that can stop this are drive encryption applications (including bitlocker).

Hi cluberti,

Thanks for those suggestions, I don't have any drive encryption applications installed and after changing the paging file size manually and setting it the dump size to "Complete" I found it still would not resolve the problem. Undeterred by this drop back I decided to do some "out side the box" thinking. My first hunch was based on the fact that I knew I was having problems with my antivirus software so I decided to just disable it and see if that changed anything. To my surprise when I manually initiated the BSOD the crash dump file was created and the computer restarted.

Since Avast Antivirus has several on-access scanners (I was running 4 out of the 7) I decided to turn each of them off one by one to see which one was causing the problem. A while later I found out it was the standard shield provider that seemed to be causing the problem.

After disabling it I made my system hang and forced a BSOD, to my surprise I found that it didn't want to create a crash dump file despite having the specific on access scanner disabled. In order to make my system hang I need the Messenger on-access scanner enabled so I can't completely disable Avast antivirus in order to make my system hang.

This just proves that my AV software is the cause of this problem and I will be explaining these findings to the developers.

In the meantime I just want to thank you for helping me make sure everything inside the box was properly looked at so I could move to the outside .

Not a problem - always glad to help, especially with the easy stuff