Finaly, I have managed to get rid of SP4 - was a bitch because it wasn't showing up in 'Add/Remove Programs'. Then in Safe Mode, installed SP3 onto my system. Rebooted and downloaded about 50Mb of security patches and updates. Installed IE6 (SP3 reinstalled IE5.1) and the Google toolbar and from first inspection, all appears ok.
I can now visit
www.bbc.co.uk again and forums like this one appear firt time, no need to refresh. I have tried a few applications and they all worked (so far), next is to install hardware and software I couldn't get to work under SP4.
I guess the old saying is right >>
'don't fix what ain't broke'