If you have not un-installed the newer version of NI-DAQ, you should do that first, then try installing the 6.9.1 version.
If you continue to get errors, there's a utility available from NI that will clean up all references anywhere to NI software so you can do a clean install. During the reinstall of LabVIEW, be sure to do a custom install and tell it not to install any drivers. Then install the 6.9.1. Ed
