Avast anti-virus is the most trusted free anti-virus that is available in the market. As, it provides not just a security but more than security for a computer. The Avast anti-virus scan engine is very much lighter, installation package is smaller in size that installs and runs on your computer more easily than other anti-virus.
Recently, avast has rolled out its newest version of anti-virus, called Avast 6, that is available for free download from the avast official site. This newest version comes with a powerful Sandbox feature, that allows your computer to run unknown and untrusted program in a isolated space, where they can’t harm your system and also, in the paid version there is another feature called Safe Zone, that increases the protection of your data while transferring it online.
Avast 6 is compatible with Windows Xp,Vista and 7 and can be downloaded from here.