I know We can uninstall a windows application using its MSI by passing command arguments as follows,
Process p = new Process(); p.StartInfo.FileName = \"msi
This command works on the command line:
msiexec /x {3A40307D-6DF2-4412-842F-B1D848043367} /quiet
I haven't tried it in C#, but replacing your arguments with the key shown above should work. You can find the GUID in the registry key for the app you are trying to uninstall.