If you like the user, update all the programs, ask her what she wants to add,... And actualize the backup.
Repeat from step 3.
There should be no antivirus, no firewall and no anti-spyware software needed. Restoring image-based backed-up system partition takes at most 10 minutes on modern computer. Important thing is to carefully set up the system, so that all user's data (e.g. Firefox profile) is stored to another partition. And you should not forget to check for new files on the system partition before restoring it.
I think that protection of home computers is overrated. I have this simple solution:
There should be no antivirus, no firewall and no anti-spyware software needed. Restoring image-based backed-up system partition takes at most 10 minutes on modern computer. Important thing is to carefully set up the system, so that all user's data (e.g. Firefox profile) is stored to another partition. And you should not forget to check for new files on the system partition before restoring it.