Thanks Pete, I went for the Kingston, being a little dearer but with a good warranty.
Replacing the keyboard was a tad tricky, getting the ribbon connector in properly, but I practised with the old one first and it worked first time.
Then to add 2 X 1 GB ram chips. Interestingly one web site said "The first socket may not be user accessible. Please consult your system manual...".
Hmmm.
Well I youtubed for videos of people changing RAM, there are plenty out there, one chap was specialising in Dells, and he mentioned that sometimes socket one is under the keyboard. Which I had just replaced.
Well, I went through the bottom to get at the first chip, and lo and behold, there is the second chip positioned just beneath it. Click, pull, click, pull ... push, click, push, click ... done.
The first time I fired it up the desktop Icons were strobing, but that went away when I restarted, so, all is well.
And maaaaan it makes a difference. The machine used to jam and freeze and have confuptions whenever I asked it to do more than one thing at a time. I guess half a gig of RAM just don't cut it nowadays.
Thank you all.
/thread.