how to use this avast antivirus? ive scan my whole pc and got a few virus.then i put them all to the virus vault (chest).but how to delete the virus? how this thing works? what if i delete them?

no need to delete them if they already moved to the vault. nothing can access them from outside the vault nor can those viruses infect anything outside the vault.

what about if i scan thumbdrive? then if i put the virus to vault,is it the thumbdrive safe to use? and if my avast expired after 30 days,what will happen to all the virus in the vault?

it should be safe to use

register again lar before expired

don't worry. the vault will still be there with the virus inside even after the expiry date. you can still use the avast free version as long as you register it online. the vault is actually hidden so you cannot manually edit it and release back all the viruses.

you can also try using USB antivirus from TECH TITAN

you can also try using USB antivirus from TECH TITAN. it helps remove virus from usb.