Only just read your post - and my first thought was the power supply. Glad you got it sorted. On the 'BackWeb 8876480 exe' issue - all you have to do is enter it into a google search and it comes up with the result:
'backweb-8876480.exe is a process that comes with the Logitech Products software. It manages the automatic update check as well as providing you with new for the latest offers and products from Logitech. This is a non-essential process. Disabling or enabling it is down to user preference.'
So, google is a perfect starting point to work out whether a process is a virus or yet another program trying to access the internet that you arent aware of!
