error code 18

[hectified]

If you are getting "error code 18" in Windows DO NOT use Ctrl Pnl Programs and Feature Uninstall as suggested by Spotify.  It leaves too much **bleep** and you will be left in no man's land, unable to install OR unistall.  Use Revo THEN reinstall. If too late, stop all Spotify processes in Task Mgr, reinstall and THEN Revo Spotify.  Finally you can do a working Spotify install.
The Spotify coders HAVE to write a more robust uninstall routine.
If you don't have Revo in your toolbox have fun removing traces of Spotify in %appdata% and your Registry.