In a rude awakening today, some 64 bit Windows 7 users who utilize AVG anti-virus experienced a blue screen of death (BSoD) today after a required reboot.
AVG has acknowledged the issue and has pulled the offending update from its site, however for those who have already suffered damage a non-standard fix may be required.
Firstly, if you have not installed the update 3292 yet, you should be safe as it has been pulled.
If you have installed the update, but not yet rebooted, then manually delete avgrs[x|a].exe and avgchsv[x|a].exe file from your computer.
Selecting "Last Known Good Configuration" or system restore options my not fix this issue. Instead, AVG advises users that have experienced a BSoD to use AVG's Rescue CD which can be found in this link. Once the system has launched with the CD, select Utilities and then File Manager. Next you have to get to the drive, usually this is /mnt/sda1/. Now you need to get to the right system folder, so navigate to Windows/system32/drivers/. Now you can banish AVG files from your computer by renaming them. AVG believes that in this case, all you need to do is rename avgrs*.exe and avgchsv*.exe but if you are really worried you can find all files starting with avg (e.g. avgldx86.sys, avgtdix.sys, etc.) and change the extension from .sys to .bak. Now you can remove the Rescue CD and reboot your computer by pressing ctrl+alt+delete.
When queried as to why this happened, AVG tech support replied that improperly published AVG CTF files were to blame.
Sources: CNET forums and AVG forums