There is some programs, that is not malware by itself but provide unwanted, and unneeded services, consume %CPU and RAM and really annoying.
For example, I install some soft, that i want, but if I forget to make many mouse clicks (like go to custom, and uncheck some boxes) i will get also changed my browser default page and search, bring bar, yandex bar, [at]mail.ru agent, [at]mail.ru guard, [at]mail.ru sputnik, [at]mail bunch of unwanted ■■■■.
So, make an option to block any changes in my browser homepage, bars, search engines, screensavers, wallpapers and all stuff.
And make option to block any installation from some vendors like mail.ru, yandex, yahoo and other unwanted malware dealers.
And block autorun attempts. If some stuff tries to modify autorun (ie startup, or creating a service or autorun registry key) it is unwanted with 95% probability.