Download the McAfee removal tool from
here or from Pondus' link above, and run it.
What does "mpt" mean? That you are on an admin account? If so, good, if not, any security application is best run-as an admin.
After running the tool, reboot, and attempt to install Avast again. There doesn't seem to be a removal tool for Paretologic products; which one did you install? The AV? Did you reboot after uninstalling it?
Where did you get your Avast download?