I do apologize that you have been experiencing issues with the setup of your Slingbox 350. To complete the setup you would need to use the Slingplayer for Desktop. You should be able to get the setup option for your 350 in the directory. However, if you do not see that option please try the troubleshooting steps provided in the link below. Please let me know if you still experience issues with this.
Sling Media Moderation Team