Internet Explorer opening itself in the background
 

Hi, please help me get rid of this nuisance. It opens sometimes in the background, or with an ad or annoying sounds. Logfile of Trend Micro HijackThis v2.0.4 Scan saved at 12:57:18 AM, on 22/09/2010 Platform: Windows XP SP3 (WinNT 5.01.2600) MSIE: Internet Explorer v8.00 (8.00.6001.18702)...