The Deauthorize button cuts off access to the SpiderOak servers from a device. Once you deauthorize a device on the web, the SpiderOak application on this device will show "disconnected". You will not be able to upload or download from a deauthorized device.
If you lose a device or it is stolen, you should immediately deauthorize it so that no one can use it to access your account.
If you accidentally deauthorize a device, you can re-authorize it by manually deleting your application data directory on the deauthorized device, then running SpiderOak again. SpiderOak will prompt you for your username and password when it restarts, and you can choose that you are reinstalling the deauthorized device. After syndication completes, SpiderOak will reopen and you will be able to continue using this device normally.
To uninstall SpiderOak on Windows, first close SpiderOak (otherwise you will still have scripts running which will write more information to your appdata folder). Next, choose 'Run' from your Start menu on your PC, then type %appdata% in the Open prompt box. This will open an Explorer window called "Application Data" which lists folders for all the applications you have installed on your computer. There will be a folder in here named "SpiderOak": delete the SpiderOak folder.
To uninstall on a Mac, please open Finder and look in YOUR_USER_DIRECTORY. From there, open the Library folder, then Application Support. (To access the Library folder on Lion: 1.) Open up a Finder window 2.) From the "Go" menu, select "Go to Folder…" 3.) Enter "/Users/
On Linux, please delete your rename your ~/.SpiderOak folder.