Engineer ... thanks for that extra. I've just looked in the relevant Registry directories and the background tasks that I've taken out do not appear at all. Interestingly, after rebooting, I did not see "a little box keeps telling you that you are using this process".
I don't have much reason to have MS Word open when I'm online, tho it HAS happened. More likely to have Excel open, plus a few browser windows, plus my e-mail program (Eudora), plus my anti-spam program. I haven't had a lockup today - yet - but that's probably only because I haven't used my computer very much today...
Shall make enquiries tomorrow about increasing the RAM.