I've found today that my computer wont open folders and some programs. When we click on any folders or open anything thats in a folder, the entire screen goes completely blank with the desktop wallpaper visible for a few secs then goes back to normal like nothing has been selected with little to no processor effort put into the execution. We tried a system restore and get a message that it cant be done. Virus scans get nothing either. The only thing that seems to work at the moment is safe mode with networking. Any ideas on what could be causing this? Thanks.