Its dual core CPU runs at 2.20GHz. I expect a PC to last longer than 3 years! I have just re-formatted my hard drive and re-installed everying. Before doin that there was to problem with playing video clips. I am now finding that quite a few sites want to install flash. The previous version was lost in the re-format. Is it too much to ask to have a version that is not so resource hungry?
Finally got it to work! Tried installing from the archive before at least once. This time I logged on to Firefox as the administrator and disabled anit-virus software first. Looks like I cannot have tried the same combination before.
Discovering how to use "run as" helped. You do not start download as administrator, so it seems, but Firefox. Thanks for helping to focusing my efforts.