Then why do we not simply force the use of the windows security center into all windows builds of bitcoin by default (or enforce the windows security center to be running unless the user is "advanced" and clicks otherwise)...
The windows security center for those are are not aware is a notification nag system on windows that constantly nags the user to download the latest virus scanner, make sure their firewall is up, to enable the virus scanner and all updates, etc...
If every "basic" windows user was forced to do this by default, I think we could cut down on 90% of the possible thefts by trojan at least - all without much work on our part.
My sense is that most users who are compromised by malware and viruses are actually running the Windows security center. However, I'm not strongly opposed to the idea of the client warning users if their system seems insecure. (Though this could clearly get ridiculous. I don't see any point in having a huge table of specific issues we check for. Oh, you don't have this patch. Your version of this DLL is too old. And so on.)