又一个死机问题：

又一个死机问题：

When the machine is open, Windows98 can be started. Then another program was automatically open, but cannot be closed, even from Task Manager with ctl+alt+del. Suspect virus or system files missing(maybe deleted accidentally). Norton 2003 was installed but can not run (the same software was tested on other machine, it run well) because of the other opened program.

So, in short, the machine often freeze, saying some files are missing. Questions:

1. how to recover system files ?
2. how to scan for virus?
3. How to recover existing documents if re-install windows must be done ?

Thanks.