That is great. I will check back later to see if you have any information for me. Thanks much for what you have all ready dun for me.
Seeing as you've voiced concerns about affecting usability, I'd recommend adjusting the UAC (Start -> Control Panel -> User Accounts and Family Safety -> User Accounts -> Change User Account Control settings.
There is a slider there that explains the different levels.
Basically what this will do is notify (make the screen greyed out with a pop up) when certain actions are about to take place, such as installing a new piece of software. This just makes sure you actually want to install/change the settings, so if something comes up unexpectedly then it's probably something you don't want to run.
This shouldn't affect usablity too much, but it will add a layer of security. Obviously it's not the best solution, but I think, given your concerns, it's appropriate and suitable.