The first thing to ask yourself is IF you have a virus. Why do you think so?
The second thing (if the answer to the first question is "yes") is to download a bootable antivirus (a .iso-file) from another maker, burn that to cd, boot from it and see if that does find it.
This is an example: https://support.kaspersky.com/viruses/rescuedisk Other makers have them also.
i am new user of this forum. i am using avast anti-virus for my pc protection. but avast can not find the virus. now what can i do it?