okQ: If used as a webserver, is there any difference? Or which one would be better, in wat sense? A: Windows 2K server, advanced server have IIS installed by default. The main difference between adv server and server is that the former supports CPU clustering and larger addressable memory address. So unless you have the hardware, don't bother with adv server. Q: Does windows xp has connection limits? A: WinXP can only accept 10 concurrent connection to IIS.