Mark, Troll, Whickerman (interesting??!! been burnt yet?)) and Postdog..... thanks for the replies. Still not sure. Been offered £450 for my machine and can get a thinkpad (2nd hand) with similar spec (except it has a 128Mb nvidia card) for £600.
inclined to keep given what Mark says about going wrong within a relatively short time. I had problems with XP kernel (got the blue screen of death - physical memory dump!!!!!) and I have to say that Dell were great about sorting out.....phone call to them (courtsey of nomore0870) in india, courier arrived next day, machine back and sorted 4 days later! Going well.
Thans again folks for your time
Shalom!