I would not say that " infected files come back again and again " , but that false psitive Redlof come again and again !

disable  and enable the Systemrestore the files should be gone. 

Yes ,all of the files would be deleted …BUT all checkpoints to recover the System would be lost ! And now I have many patches that I could have to uninstall .
I have posted because I beleved that Alwil members
were interested to a false positive…Just to get a more
reliable Avast!4 .

Regards , rolando.