New Windchill Install - Which Windows OS

Hello,

Ihave to install Windchill PDMLink 9.1 for the first time. I'm currently running the Intralink 3.4 fileserver and client on Windows XP.

For the Windchill server machine, what is the best Windows operating system to use? I only have XP machines, so I assume the first step is to upgrade the server OS.

My machines are 32 bit, so does that mean Windows Server 2003 is my only option?

Thanks,

Steve