Thanks for the advice. I uninstalled Spyware Doctor and reinstalled LW. It worked perfectly for about half an hour, something which was not possible before as the PC restarted after max. 5 minutes of running LW, so I thought it was fixed. But then my sister opened Real Player to listen to something and there it went again... After restart, I ran LW without opening any media player and so far it's been running without any problems for 2 hours. My question now is: does this problem make sense? Should I not be opening any media player while running LW? Anyway, thanks again very very very much!