AVG Free is a version of the AVG antivirus which is free for private and non-commercial use. It can only detect viruses; it cannot remove them from files. Others antivirus running on Ubuntu can be found here.
Installing AVG Free
- Download the linux version (.deb file): 
- Double-click on the file then click on the Installation button.
- Open a terminal (Applications -> Accessories -> Terminal), and enter these commands:
sudo rm /usr/share/applications/avggui.desktopsudo gedit /usr/share/applications/avg.desktop
- It should open a text editor, enter this text in it and save the file:
[Desktop Entry] Name=AVG Antivirus Comment=Antivirus Exec=gksudo avggui & Icon=/opt/grisoft/avggui/prog/pixmaps/avgico_big.png Terminal=false Type=ApplicationCategories=Application;System;
Click on "System-->Preferences-->Main Menu" To launch the menu editor. Find the AVG entry in Accessories (for Ubuntu 9.10 the entry will be in System Tools). Right click its entry and select Properties. In the "Command" box add gksudo to the beginning (ie. make it look like this "gksudo avggui") Click on close for the AVG option then the same for the menu. You will be now prompted for your password when necessary as AVG will only run with your password being supplied.
Using AVG Free
- You can now start AVG Free by going to Applications -> System Tools -> AVG Antivirus.