Thanks for the quick response. My laptop is only 3 months old and I am running NVIDIA GeForce Go 7400 for my video. I use my laptop a lot for all sorts of things and registering FSUIPC is the only thing that has ever given me a problem so I don't suspect faulty memory (I have 1024MB RAM, an 80GB internal HD, a 100GB external HD where I keep all my FS2004 files), the processor is an Intel Core Duo T2300 running at 1,66MHz.
I don't know what windows blinds is I'm afraid. I am running the usual stuff like mail checker (set for every 30 mins) and Kaspersky Internet Security 6.0 (which I turned off and tried to register FSUIPC, but with the same freeze). There is nothing added to my machine that modifies Windows. I checked about 6 weeks ago and my video driver was up to date, I'll have another look but I'd be surprised if it is that because I am not running old anything on this 3 month old, all up to date, lap top.
I'm still scratching my head and would welcome any help.