Try this... It happened to me in vista... and I used avast ----- (bought yes!) and the problem has never happened since... Download Avast ... Home--FREE EDITION: http://www.avast.com/eng/download-avast-home.html Or upgrade to ---... Run Avast and see what it detects and deletes... Hope that helps... also Download this program Crap Cleaner (yes Crap!!!) http://ccleaner.com/ it is a freeware program like norton and macafee but doesnot use up your memory or hd space..it if free and works as a charm mostly it is self explanatory but do visit site if further help needed! Also set Crapcleaner to start a sweep every start..meaning everytime you start it will do a sweep and delete uneeded and unnecessary files off your comp plus the temp folder and etc etc... and let avast run on startup and all the time I havent had any problems on vista and i doubt you would also -N