cannot start or uninstall Spotify on Windows 7 64

[austint]

I am running Windows 7 64 bit on two different computers and after some updates I found I was unable to open Spotify or uninstall it. In both cases, simply nothing happens. I tried uninstalling using control panel>>uninstall program, and using CMD or RUN (c:\users\UserName\AppData\Roaming\Spotify\Spotify.exe /uninstall), and all failed. In all cases, there was simply no response. FYI, I was running as admin.  If I went to try uninstalling again from control panel after a first attempt a message would say "Please wait until the current program is finished uninstalling or being changed." I also tried uninstalling in safe mode, and that failed too. Any ideas?

[bbedo]

If you keep getting this error, try opening Task Manager and killing any msiexec.exe processes that are running.