Error during update from version 12 to 13

Hi, our company is using teamviewer since version 6. We have many clients which are working just fine, but one computer has a problem: During the update process from version 12 to 13, I get the message "error launching installer". When I start UNINSTALL.EXE from the old teamvierver version 12, I get the same message. How can I wipe teamviewer from this computer, so I can install version 13? Claus-Christian Ude MEDLINQ