Will Windows allow me to change from Pentium 4 to C2D?

There is this computer in my mom's office with an old P4 3.8GHz that makes more noise than a jet at take-off.
So, I was thinking of putting in something like an E5200, but I don't know whether Windows 2003 Server will accept it. Reason being that I'm scared that Windows will think the hard drive's been moved to a new machine and refuse to work.

Anyone here care to give me some advice.
Quick advice will be appreciated. That noise is going to drive someone to a mental breakdown

Cool, thanks for the quick reply daship.
It's a 965 motherboard (LGA775). All it needs then is a firmware flash, at least that's what I hope.

afaik, cpu chance can work but mb change requires system reinstalling, in general, I would recommend reinstalling the system if you switch mb or cpu, the rest will work ok.