well my suggestion using comodo internet security or AV they are good for free
As I know AVast asks online registration so it does not fit to offline laptop.
And how about comodo? Is there possibility to update it database offline (by downloading it in the other PC)?
It will be good for old slow laptop?
Doctor Rob :
If the computer is 100% offline and never has any things plugged into it that were online (like if you got a new thumb drive you were downloading stuff to from another computer you don't need anything.
IF you always check the stuff on the other computer that has good protection then I dont see any reason you would need antivirus on the OFFLINE computer.
There will be cases when I will use some unchecked stuff installed from USB Flash drives or CD/DVD.