Hi all, Looks like after spending most of the night dicking about with this thing, that it is indeed the Bugbear virus thats been suggested.
I downloaded the Panda Active Scan and did thier scan which found 8 infected files, which were fixed.
This enabled me to go to the Norton and do thier scan, which turned up nothing.
The computer shuts down now in the proper way. The next thing I try will be my emails and hopefully the buggers no longer linger.
Much thanks to all you good people, for the support and advice.
All the best,
Glen