This is a free anti-virus program, which will allow you to keep an up-to-date virus program on your computer. This is a program that you really do need, especially if you don't have an anti-virus program or have one that is not up-to-date.
If you have an up-to-date anti-virus software that you trust, then you can ignore this program if you choose, but be sure to use some type of anti-virus software.
AVG updates automatically over the web so you are always protected. AVG also features real-time protection, email scanner, and a virus vault.
This program is free for home use, not business use. There are paid versions available for added features and for business use. It runs on Windows and Linux.