|I would suggest to download "Avira AntiVir Rescue System".|
This is an ISO file and must be burned to cd.
Then reboot your system from this cd.
At the first bootup screen simply press enter.
When the system is fully started, click the update button, to use the latest virus definition files.
Click the configuration button and let Avira repair or rename the infected files.
After configuration click the button to start scanning.