as anand said, it most likely looks like a bad uninstall of either of the two AVs. download the mcafee uninstaller and then try again. also goto the registry editor and delete any reference to mcafee and/or avast before installing again.
oftopic: just 1 dialog box in the bmp file.... takes up 1.4mb and when compressed in .zip format becomes 9.2kb!!
edit: oh saw ur edited post now. so i think something is remanant from the prev. install. u need to hunt it down. i'd seriously suggest kaspersky or nod32 (both paid) or even AVG (its free). all are much much much better than mcafee!