There are different version of redirector programs. You've probably accidentally clicked on a link that has allowed the program to change something on your PC.
What's the program and website?
Here are some suggestions:
Suggestion 1
Go to Tools -> Internet Explorer -> General
Change the homepage address to
http://www.google.co.uk/ or whatever.
Click apply.
Suggestion 2
Check the properties of your internet explorer link
It should be something like "C:\Program Files\Internet Explorer\IEXPLORE.EXE"
The program may have included something after the .EXE
Suggestion 3
Try downloading
CCleaner
Suggestion 4
Try downloading
HiJack This
Hope this helps.