[KeithT]

Thanks everyone for your advice. My current machine was custom built about five years ago. I have an AMD Athlon XP2200 processor, 1.8GHZ with 1 gig of RAM and Radeon 7000 series video card. So not a tremendously well specified product. But then it is quite old now. I will be getting one of the DEL XPS models soon. I will look into the 64 bit question.

Flake, some points from the article link you posted:

Pros and Cons of a 64 bit system:
You can address much more than 4GB of memory, which is ideal for avid gamers, CAD, video editors and heavy multi-taskers. However, any 32 bit software you use will still be restricted to 4GB memory – you need a 64 bit CPU, OS and applications to take full advantage of the extra RAM.
16 bit applications will no longer run. Although this is unlikely to be a problem, if you use very old software (from the Windows 3.1 days!) then it will not work under a 64 bit OS.
Existing 32 bit drivers no longer work.If you have older or poorly supported hardware you may find that it can no longer be used. Got a 7 year old scanner that just about works in Vista? You may not be able to get it working in 64 bit Windows 7.
Unsigned kernel-mode drivers no longer work. Along with the issue above, the inability to run unsigned kernel mode drivers will cause problems for old hardware. (There is reportedly a way to bypass this check).
Running some 32 bit applications on a 64 bit OS could actually be slower. The additional overheads in running 32 bit software in 64 bit mode could cause a slight degradation in performance. It will take some time for 64 bit software to become the norm.