You can change homepage to anything you want....
Go to settings, then control panel, then to internet options,
When internet properties box comes up the first line is Home Page.
You can change this to whatever you want eg.
www.yahoo.com
The site has more than likely put in a folder in your program files folder.... You will have to find this file and delete this BUT make sure you know what file your deleting........getting rid of a wrong one can be really bad
Hope this helps