About Servers,

I have 2 Servers run Microsoft Windows 2000 Server. Server1 is DNS Server, DC (AD has integrated). Server2 is DC too but use the same DNS with Server1. Now I want to reinstall Server1 so that systems get high performance ’cause it run unnormally. What’s the best way to do so that my system can still run good?
Thank you very much,
Regards,