My Internet Explorer has been hijacked (i.e. my browser web page cannot be changed from a site that I don't want). What can I do?

Download a copy of AVG Anti Spyware from here and do a scan.
If that doesn't work, download a copy of HijackThis from here and post the log back here and we will have a look for you

Download any free anti-spyware program that can help you from hijackers
I recommend you to download the program called Spyware sweeper
This will manually remove the spyware, which is hijacking your browser.