Internet Explorer

[#1]

My PC has XP Pro and all of the latest updates. I normally use Internet Explorer set to "www.google.co.uk". Now, somehow, it keeps changing to www.search/babylon.
I have tried going into Control Panel/Internet Options and resetting to Google, then Applying and Exiting, but this seems to be a short term solution. The next time I try to use Internet Explorer, it comes up with a message that something is or has tried to change the default setting - did I want to stop that change, or allow it . It doesn't say what the change is going to so I dont know if it is telling me it is trying to go to google, or it is tring to go to Babylon.
Incidentally, the Search panel on the IE window mentions Babylon, even after I have done the Control Panel change.
How can I get rid of Babylon?
TIA

[#2]

Not nice http://www.sevenforums.com/browsers-mail/212495-ie-9-babylon-search-engine.html
I think that the only way to get rid of it is edit the registry
http://www.techimo.com/forum/networking-internet/268235-help-remove-babylon-search-malware.html
however this may work
http://www.raymond.cc/blog/babylon-toolbar-adware-info-complete-removal/?utm_source=feedburner&utm_m...

[#3]

Thankyou OldJim. I used your last suggestion - the raymond method. I did what that suggested, adapting it for IE8, where it dealt with IE9. I noticed at the end of it someone had said they used Spybot, so I used that too.
I have also done a search on the C: drive looking for Babylon, and deleted any I found, have gone into Zone Alarm and removed any mention of Babylon,and I have run CCleaner though not sure what that one would do.
Now, after several tries, with a reboot before each try, IE doesn't mention Babylon at all, so hopefully, it has gone from my pc. There is always the worry there is still something hidden away. Only time will tell
Thankyou for your help