Cleaning a infected system with Bootable Anti-virus

In the previous post Things to do for cleaning a infected system we see about how to clean a infected system, with boot-time scan. but in some situations, Anti-virus products are not installing, because of the virus. so in this  post we see how to clean that heavily infected system.

Things to do for cleaning a infected system

Read this post if you are in any of the following conditions
-- your pc infected with virus.
-- or you in a doubt that your pc is infected.