Looks like something is going wrong with an MSI database query, though it's not clear what the problem is. A log of the uninstall process may help. To generate a log, you'll have to launch the CVI 8.5.1 installer from the command line. If your CVI 8.5.1 CD is in drive D:, run this command:
D:\setup.exe /log "C:\<some path>\ log.txt"
Running the installer when the software is already installed will begin an uninstall. After the uninstall errors out, post the output log file from the path you specified.
Mert A.
National Instruments