the wireless card is not ancient, although not brand new. It is a Netgear PCI MA311. A trawl of the net suggests that Orinoco is not the best driver for this card although that is what seems to be referred to in the scripts I saw somewhere.
If I find a better driver, do I need to re-build the whole OS to install it? Sorry I am new to Unix at this level.
The memory test ran through 9 times in about 7 hours before I stopped it. It flagged up that it had found 6 Gb of ram, I don't know if the version of Ubuntu I have is 32 or 64 bit, I guess there is an easy way to find out? I got the CD from a friend who had downloaded and created the "Live" CD it from the Ubuntu free site, I understand.
Will a disconnected wireless card still have any activity in the system? I will try unplugging the card, tomorrow.