C:\searchpage.html

What is "C:\searchpage.html" and why does it insist on being my homepage? Also what is perfectnav and smartfind and all these other things im starting to see instead of the old Cannot find URL. I''ve run adaware and found 789 objects. I have not seen perfectnav since then but that was 5 min ago. But this C:\searchpage.html is just some searchpage on my c drive, I delete it and it comes back, I change my homepage and it comes back. Is this a setting from the browser? If I type in "www.gamedev.net" it trys to search for it instead of navigating to it, unless I put "http://" in front of it.