Recently my PC has shown empty files- (system volume) Profiles are missing. I installed a Google/Yahoo tool bar, half of it gone. I cannot install an antivirus due to c drive being so full. I have defragmented, deleted unecessary files, and did a system and disk check-( it tells me its healthy ) I cannot install or download anything. If it goes through the process, I will look for it and it will be on that drive, but it wont open. No response at all. It also gives me error messages that certain software cannot run without windows service pak. (I have it.) I cannot open docs in word. .. If I