Thank you all.
I have done a surface scan of the disk and it doesn't help, nor does running it in safe mode.
I am beginning to think that the PC in question has dodgy memory, so I am going to take along a couple of spare SIMMs when I next go and see if that helps.
I may well ask for the 98ME prog, but my experience of ME was that it was the greatest heap of !!!! that MS have produced since Windows 2.0, so I am a little wary of it!
W