You have an infected system file, so this could end up being tricky, but we'll see what we can do. Go here:
http://www.eset.eu/online-scanner to run an online scannner from ESET.
Note: You will need to use Internet explorer for this scan
Check the box next to
YES, I accept the Terms of Use.
Click Start.
When asked, allow the ActiveX control to install.
Click Start.
Make sure that the option
Remove found threats is checked, and the option
Scan unwanted applications is checked.
Click Scan.
Wait for the scan to finish.
Use Notepad to open the logfile located at C:\Program Files\EsetOnlineScanner\log.txt
Copy and paste that log (or attach it if you wish) as a reply to this topic, along with a new HijackThis log and new ComboFix log.