Did you try rebooting as the error message suggests?


Actually, think it would be safer to have the copy of the avast! installation file first before removing it and then going out on the 'net to get the new one. Use another system and leave the affected system offline until the avast! install takes completely on it.

Maybe I’m reading this all wrong, but one should not venture out without protection?

Links: http://singularlabs.com/uninstallers/security-software/
http://www.avast.com/en-us/uninstall-utility
http://www.avast.com/download-software

Then, as Staticguy says, run Rejzor’s tool linked to above.