Many thanks to all who have responded
Having read through all the replies, and done my best to understand them, it seems that I either have a driver (for XP) issue, and/or a DirectX issue:
Can somebody please tell me what DirectX is or, more importantly, how to determine if it is on the XP laptop?
Also, how do I list drivers in my Vista machine? I will then (hopefully) manage to identify the driver which is working under Vista, and start a search for a suitable XP version...
Drapes is right... Feckin' puters
Maxbert