Since you have AVG Antivirus security program at system...
Open the "Start" menu and then choose the "Restart" button. Wait for the logo of your computer's manufacturer to pop up on the screen, and then press the "F8" button repeatedly until a new menu appears.
Starting the Computer in Safe Mode
Highlight the menu entry that says "Safe Mode," and then press the "Enter" key. Wait for the computer to finish loading, and then open the "Start" menu again. Right-click on "My Computer," and then click the "Properties" button.
Click the button labeled "System Protection." Access the "System Restore" tab, and then click the "Turn Off System Restore" button at the bottom of the window.
Close the window, and then open the anti-virus program. Run the anti-virus program's update feature by clicking on the "Update Now" button. Disconnect your PC from its Internet connection either by turning off your wireless router or by unplugging your Ethernet cable.
Scanning for Virus Software
Wait for the update process to finish, and then click "Computer Scanner." Click on the option to scan every drive and device connected to your computer.
Click the check boxes next to each of the Generic2 Trojan virus entries that the anti-virus program discovered. Click "Remove Selected Problems."
Turn the "System Restore" feature back on and the re-connect your computer to its Internet connection. Restart the computer to finish removing the Backdoor Generic2 Trojan infection from your machine.