Okay gregrocker I know you are trying to help, and I appreciate your help but I find your comments a bit pushy. Maybe I am on the wrong forum?
I have Driver Manager installed on my XP installation, not in Windows Seven, thanks to advice. It doesn't seem to be doing any harm there.
I have run the basic "Check Disc" command in my version of Windows Seven and it came back "Clean". I ran it with the following options:
-Automatically fix file system errors
-Scan for and attempt recovery of bad sectors
I am slowly getting through the lists of diagnosis test etc. you helpfully suggested in a methodical process but I don't have much time to spend on this.
Thanks for any additional help.