Website...

Hello everyone....

Whenever i open internet explorer i would normally have a
homepage (yahoo) but now when i open it
http://www.jetsearch.org/ comes on which is rather
annoying....because even if i change my homepage back to
yahoo....if i close the window, then open internet
explorer again, it goes back to the jetsearch site....i
find this really frustrating, what can i do to get rid of
this??

All advice is welcome...thank you