Repairing Win95

One of my workstations was infected by the SirCam32 virus. Using Mcafee & some Microsoft tools I was able to remove & repair the PC to the point where it seems to function normally. But?? many functions like Control Panel, Scandisk, etc. are now notavailabe or an error message appears when an attempt is made to start these programs.
Should I re-install the OS (Win95) & what are the steps to do this safely without having to lose all data on the drive??