Got another one this morning whilst my wife was trying to connect to the internet. Having followed VOG's advice and turn off 'automatically restart' wife was able to write down the error.
It gave the STOP CODE 0x00000050 (which could mean a host of things) but more importantly it mentioned a problem file being VSDATANT.SYS.
After a little research it appears this is a Zone Alarm file and is causing many others problems as well. It looks like I may have to uninstall and wait for the next update. It hasn't been mentioned on PC Advisor so with so many forumites using it I thought I post it to see if other were sufferring from the same. The cause of the error is not clear.
Can anyone else shed any further light on the problem?
What version of Zonealarm are you using? If it is the latest ver 6 something then I had the same problems as you. I uninstalled that version and went back to version 5.5.094.000 and have had no problems since.