How do I get rid of ….hp.uti?

Apparently I have been struck with a virus or at the least a Trojan (specifically Download.Trojan and Trojan.Byte.Verify. I have run Norton A/V and deleted the files identified in quarantine, but it keeps appearing as my home page in IE. IE is not working properly either. I get an error message which I can bypass only by moving the dialog box to the side of the screen and ignoring it. However, my surfing does not reach every screen I’m trying to access. HELP!