discovered that you can see what damage FP did on startup: see file aswboot in directory c:programfiles/alwill software/avast4/data/report/aswboot.
At least you then have a list of the files that were deleted!
First I used http://www.piriform.com/recuva to search for recoverable files of programs of wich I hadn’t any backup or aren’t freely available. Without the first list it’s unlikely you can filter the missing files out of the recuva list.
Afterwards I reinstalled entire programs that were free versions (via cnet or else) of witch files were deleted.
Will make a bootable backup on a USB-drive or stick in the future. It’s annoying if you’re airbag causes damage instead of protecting you!!!
Avast should warn and only become active/installed when it notices a backup and/or vrdb is available of recent date. This could be a proper ‘foolproof’ measure to protect the user.