When I scan the memory I can not delete the viruses because the apply button is inactive.
(When I scan the discs that ok.)
What can be the problem?
Plz check if you have already told avast! how to deal with viruses.
Go to Settings–>Action.
Plz check that and report
malware detected in memory is just detected and automatically blocked in real time when it happens. Scanning the memory manually will just inform you of malware running there if any, but without the ability to delete anything. You can’t deal with memory (at RAM level) like you deal with a hard disk, explaining why the apply button does nothing.
That is because you cannot “delete” the RAM-memory. The RAM will be deleted when you power off the PC.
Normal behaviour.
when you don’t know, don’t post 
>>> sending the users back to help files or knowledge base or stickies etc… is boring. there are tens of posts like yours - and not just from you - cluttering the forums. These posts don’t help… especially when your answer like the one here has not much to do with reality :
There’s my old french friend back again in action… ;D