Just to give you an update. I located my XP cd but instead of just fixing IE I decided to re-install XP from scratch so I moved everything I wanted to keep onto another drive and formatted my c drive and re-installed XP. First thing I then did was install AVG, Spywareblaster etc. and am in the process of updating again to SP2. Feels like I have a new pc.
Anyway, thanks again for all your help.