My wife's and my computers both run Windows XP Professional SP2. The kid's computer runs Windows XP Home. Actually have five licenses of Windows XP (2 Professional and 3 Home) and only 3 computers at the moment. Had been running the two professional PCs with Home then decided to upgrade.

Have an extra motherboard and processor here and was thinking of building a fileserver/development machine which would run Linux but not sure anymore. Might put a 5 seat license of Windows 2003 Server on the machine.