I'm sorted thanks to a suggestion at TOS.
I went to this site as suggested
http://tomcoyote.org/hjt/
and downloaded HajackThis.
I cleared out all the google and yahoo stuff and now I can get to Google the usual way.
So I've patched IE6,searched for the DNS virus using the Symantic removal tool(no virus)run three differant Spyware applications(cleared out lots of crap) and I now have a new tool to clear out those naughty redirecting hijacking programmes.
I'm wondering just how much more crap I shall have to download to get rid of the other crap and what new crap I shall have to look out for.It's no wonder a 40 GB hard disk is getting smaller by the minute.The internet is definitely full of crap.
Incog