Three suggestions to start:
You have an outdated version of HijackThis. Click here to get the latest version of HijackThis.
Run an online virus scan at
TrendMicro or
RAV Antivirus. Select the Autoclean option if you use TrendMicro.
Make sure to update Windows and Internet Explorer at
http://windowsupdate.microsoft.com.
Post a new log here when complete with at least the first two.