well, antivirus can do it. and if the antivirus are already installed and then any virus is enter into ur computer then it is possible that, that antivirus don't detect that virus, this is not always done, this done in special cases and not every time.
and if any virus already into ur computer and then after this u install any antivirus then the possibility that the antivirus will detect the virus is more then if the antivirus already installed before virus attack.
because many time some viruses delete some antivirus files or rewrite or do anythings by which that antivirus don't able to detect that virus as a virus.
Answered by
Romi
, an ibibo Master,
at
11:50 AM on July 10, 2008