Go here:
http://www.doxdesk.com/parasite/
They check your PC and tell you if you have a parasite - it seems you have - and tell you how to get rid of it.
Also, check your hosts file. Click C:, right click, click search, write hosts and search. When it finds a file named hosts, click it, choose 'select a program from a list' , OK, choose notepad, OK. ´
It should have this URL in it:
127.0.0.1 localhost
If there is any other URLs, delete them, then save hosts file. You should have your own homepage back.