Thanks for the suggestions.
I'll try them out and see how it goes. Unless they run under Windows, I can't let them have the computer for too long and I'd rather scrap the drive.
I still don't believe surface degradation or something as bad would settle in so quickly.
This disk is about 6 months old and it's quiet like a mouse. Well, it doesn't let too much data get through and that might explain that
The XP format (it runs since yesterday but the completed percentage counter hasn't even come up yet) spends its time lighting up the disk once every seconds.
The HDD Regenerator that I had tried for a while yesterday, spent two hours processing 1 GB but the lights were on all the time and it didn't find or correct any errors.
The day before when I backed up the data, XP claimed the disk was unformatted and the lights were off for some time on every access. Nevertheless, FinalData, found the data from the MFT, and after the initial lights-off seconds, it backed up the complete data with the lights on all the time and no errors.
I'm off to try some of your suggestions.
Thanks for your help.