Where to put DHCP server??

Currently our DHCP server is on an old, 400 mhz homebuilt machine running W2K. This server is also running corporate antivirus software. This computer is unstable, and has been blue-screening a couple times a week for the past couple weeks. I want to put DHCP on our brand new, $20,000+ Compaq server, which currently is only being used for file serving. Our office has under 150 employees, so we don’t see alot of network traffic. My boss disagrees with me, and wants a machine built specifically for DHCP. She says that you should never put DHCP on your main server, and not on a file server. What should I do??