You need some sort of script blocker, because Tea-Timer doesn't block scripts (and avast! home doesn't block script viruses from running.)
There are two script blockers available:
http://www.jasons-toolbox.com/programs.asp?Program=Script%20Sentryhttp://www.analogx.com/contents/download/system/sdefend.htmMicrosoft Anti-Spyware also blocks scripts + 56 other things.
I don't like to have more than on program on my computer doing the same thing
at the same time as another, (anti-virus, firewall etc.) so I don't have more than one program blocking system changes at the same time. MS Anti-Spyware seems to be the most comprehensive, so I use that.
I don't know if MS Anti-Spyware conflicts with Tea-Timer and Winpatrol, but there is always the potential that they would if they are all trying to catch the same ball...