HI,
Run hijackthis and click on scan and put check next to this:
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Bar = about:blank
Nothing open but hijackthis and click on fix checked.
Then..
Go here
http://www.bitdefender.com/scan8/ie.html and run an online scan with BitDefender (you will need to use Internet Explorer for this scan). When the ActiveX Control has loaded, click on "Click here to scan" and grab a coffee.
When BitDefender completes the scan, select the "Detected Problems" tab. Click on "Click here to export scan". Save the file as an HTML to your Desktop. Then click on the saved file and allow it to open with your browser. Go to Edit - Select All then copy/paste that log back here. Post back and let us know what it found (post the log).
And post a new HJT log also..