Please install an antivirus program, some free alternatives are AVG, antivir and Avast. (install only one antivirus!)
After installing, please update the antivirus definitions and perform a full system scan in safe mode.
How to boot in safe mode:
- Restart your computer
- After hearing your computer beep once during startup, but before the Windows icon appears, press F8.
- Instead of Windows loading as normal, a menu should appear
- Select the first option, to run Windows in Safe Mode.
finally, boot in normal mode and post a new hijackthis log here.