Ken, ran memtestx86 V3.4 for over 9 hours, no errors.
Usasma, yes I have ran the upgrade advisor and apart form a printer needing a separate driver
download, everything was OK. I also doubt if it is the VelociRaptor since it was running XP before and that would mean it went bad in the hour it took to install Win 7, not impossible but very unlikely. Also remember that this computer has multiple hard drives and is still used in XP on the Vertex SSD for between 16 - 18 hours per day without any problems.
I still don't think it is a hardware problem but I have extras here so I am going to change the RAM and try that for a few days, then change the CPU and try that for a while, then change the M/board. If that doesn't work, what a good excuse for a total upgrade !!
I ran msinfo32.exe but that is not a file I would post in public, is there any particular information you need from it?
Thanks for all your help.