Windows 2000 Professional

I have an HP 6636 I am running windows 2000 pro
on it. Some of my registry has become corrupted.
Also I cannot run scan disc I get a message that the operating system has control of the system and I cannot run scan disc even with a restart. I was wondering if I installed 2000 Pro over the existing copy if it would solve these problems?
Do you think it would corupt my my registry even more? Would it wipe out all of my existng software or would they still function? Would I ahve to reinstall all of my other devices and the software and drivers needed to run them?
Any help would be appreciated. Thanks.

E.H.