I have 4 old HP laptops (all running fine on XP, 3 Dell desk units 2 running XP 1 running 2000 no problems, two HP desktops both running XP no problems, I (i don't know what it is but it is old) running XP without problems.
One of these is used for DJing, 3 are used for Karaoke, 1 is used for recording and 1 is used on-line.
I have a New Sony running Vista no problems, but it has no programs other than calendar, booking and song list on it.