for now, as far as i've research, no virus yet able to go to the kernel level. even ur installing 3rd party anti-spyware@ any anti-virus application, the application wont perform 100% since in Vista, it wont allow any contact to the kernel level. and, vista also, have been introduce session isolation. theres 2 different session in vista, session 0 and session 1. session 0 is fo servis and all the os crap. while session 1 is for log in user crap. there will be no "hubungan" between session 0 and session 1. huhu ~

vista being build base on loophole on win2000. usually when user log in, services and lockdown user will run in same session. malware@spyware@their siblings, will try to levereage their credential in order to do anything what they want. if cannot leverage by using user credential, the spyware@else will go to service level and seek for what kind of credential of the service use. from there it will use the credential tu leverage.

using third party anti-spyware is not a bad thing. since it can help clean up ur session 1 because most of the time (very2 usually) those spyware@else came from log on user side. 

just my 2cent