Well, I started scandisk (full-strength and with auto repair) in safe mode, with the real time function of AVG turned off (I thought I'd turned it off completely!) and with the router disconnected. It has been running since 1200 hrs yesterday - nearly 24 hours and has currently reached 672,000 clusters out of a total of 1,250,000 so it looks as if i've got nearly another 24 hours to wait before I can start a defrag in earnest.
I had a look at the diskeeper lite link but am not entirely sure it will do a full defrag and it describes its function as "manual". If this means I have to watch it working and respond at various stages throughout the process then I think it will be too much to ask!! It may simply mean that it will do "one-off" proper defrags but won't work automatically on a permanent basis. That would be fine, especially if it's quicker than the W 98 version. Does anyone know, please? Perhaps I should just bite the bullet and try the official W 98 version but I don't know if my poor 10years old HDD is up to 96 hours of continual operation. "The cure was perfect but the patient died" springs to mind!!
This is a borrowed laptop which I'm using while the torture continues in the room next door.