Demage/Corrupted Register file problem

My computer crashes all the time (even when I am formatting a floppy). One time I was trying out some ultilities program -Nuts and Bolts demo version. After I finished I open other application, then an error message says that my display can't support cetain colour mode.( But it always did before)
Then it crashes after the message. When I reboot, my virshield report there is a VUL or something virus so I reboot and this time it reports there is a INvisible virus, reboot again it reports there is a casper virus, reboot once again this time no virus reported but my desktop icons are enlarged and it seemed that the display has changed setting to low resolutions. So I tried changed back and reboot but the screen went black after the window95 screen appeared...
So I restart using safe mode but it reports that my register files had been demaged and corrupted, since I don't have a backup , I reinstall win95 ver A. After that, my screen shows up and works normally. However, these are the problems:

1) I can't move or drag my icons anywhere.
2) When I open word doc, there is a message saying the    
   document can not be registed. But I can type word/graph
3) I can cut some text but I can't paste it back..
4) When I try openning netscape the window appears but It does nothing no message saying DNS error or not connected, it just sit there blank while with toolbars and blank address. When I try go to soem bookmark my mouse icon goes to wait but then nothing blank screen..

SO I think it is reguster file problem but I don't know how to fix it. Any suggestions?