Avast forum: "Unsecured" Error

Hi there,

I am using Avast 6 Home Edition version and am experiencing a warning signal: "You system is unsecured".
I tried clicking on "FIX NOW" as well as "start program". A pop up appears saying "Do you want to allow the following program to make changes to your computer?", I then click "yes", however nothing happens.

I tried running a virus scan and an error comes up saying "Unable to start scan. There are no more endpoints available from the endpoint mapper."

I even tried un-installing Avast 6 from my system but without any success, as a setup fatal error message pops up saying "Error reading product data from "c:\Program Files\Alwil Software\Avast 5\setup\part-setup_ais-557.vpz". Setup cannot continue.".

This error even appears when I downlaoded Avast 7 and tried to install it.

I don't know what else to do as my computer in unprotected and a blue screen has already appeared saying that my computer is unstable. I think I may have a virus but don't understand how Avast just stopped working. Please help.

I have checked my registration information and everything is up to date.

Thanks