Liam
Do not bother looking further into my query - I have solved it.
The problem was that because I had Spy-Bot TeaTimer running it was blocking changes to the registry and neither Hijack this nor the Microsoft Spyware program could delete the problem entries.
Once I uninstalled SpyBot and ran them again the problem cleared and my computer now appears to be spyware free.
Regards
John G7SWZ