Thanks all, the CWShredder seems finally to have done the trick.
The only remaining anomaly seems to be on start up when the 'black' page says, among other things, some thing like 'Memory manager not found', but it doesn't stay still for long enough for me to copy it and the 2 other lines down!
On the other hand, before all this I had a 'Runtime Error' on shutdown which seems to have disappeared. I guess every cloud has a silver lining! AOL Parental controls now in force!
Cheers all,
mcdhu