If I should how do I enable it? Right now its on off.
You can to set which archives avast! will test during the task processing for each resident provider but only in avast! PRO (see help file).
In avast! HE you can choose it only when you are scanning in the Simple User Interface (Menu → Start scanning → Scan packers).
Archive files are files that need to be run to have any effect for example Zip files. Therefore if it’s infected it won’t harm your P.C until it is used. I only scan the archive files rarely because the resident protection should find any infected.
I assume this is in relation to on-demand scans, but unless you have standard shield set to scan them, on the Normal, default sensitivity they aren’t scanned unless you happen to open them and extract the contents.
Archive (zip, etc.) files are by their nature are inert, you need to extract the files and then you have to run them to be a threat. Long before that happens avast’s Standard Shield should have scanned them and before an executable is run that is scanned. Thorough is also by its design very thorough and perhaps a little overkill for routine use, were a Standard scan without archives should be adequate.
I have only ever done a through scan with archives once shortly after installation just to ensure a clean start state, but with XP for example avast will do a boot-time scan after installation if you select it, this I believe will be quicker and reasonably effective. Like everything in life things are a compromise.
I think a little different.
When I run on-demand scannings, I run in the very deepest mode.
I’d rather use on-access (resident) protection without scanning opened/created/modified files. 8)