Windos Server 2003 is made for exactly that purpose, to use it as a server.
Administering is based on certified engineers, who know how to set priviledges, rights and policies.
The OS is optimized for network and disk activities, with a limited capacity of dividing processor load.
While it is possible to use drivers, it is not developed for graphics and sound effects.
It is rock solid for database, reasonable for mail purposes, and good for office application.
Using it for a home PC to play games is like driving a school bus as private car.