I have the exact same problem. I cannot uninstall Lexmark , because everytime I try it promts a message: Your version is not compatible with windows Vista" I tryed to uninstall by using the Control Panel: Uninstall programs, and by going to Programs: Uninstall Lexmark. The problem deleting files directly is that you may damage the registry and have other problems later. I e-mailed Lexmark with this problem and I hope they have come with a solution.
Betty, January 2009