Go to http://www.bleepingc...to-use-combofix and follow the instructions on how to install the Recovery Console and run ComboFix. Go through all the steps until posting the log part. Post the combofix log here.
Otherwise, you will have to post in the Windows board for this issue as it's not really malware related if all the scans come up clean. It's the DEP built into Windows (specifically SP2).