AVG isn't the greatest anti-virus.

1. Download Malwarebytes http://www.malwarebytes.org/ - (FREE), Run Scan.
2. Download SUPERAntiSpyware http://www.superantispyware.com - (FREE), Run Scan.

If it's not clean, Download and run the free trial of Kaspersky.

If all else fails, backup and format your pc and re-install your operating system.