Download KillBox (
http://www.greyknight17.com/spy/KillBox.exe). Run KillBox and check the box that says 'End Explorer Shell While Killing File'. Next click on 'Replace on Reboot' and check the box underneath that. For each of the following files below, check the box that says 'Unregister .dll Before Deleting' if it's not grayed out. Copy and paste each of the following into the top line (hitting the X button for each file - choose NO when it asks if you want to reboot until you get to the last file to delete):
c:\windows\downloaded program files\popcap loader.dll
c:\backup\btest4.scr
Reboot and report back with a fresh HJT log.