Launch, get a small window with a progress bar "downloading", Then it comes up. Also:
* It's installed in user/<my user name>/AppData/Local. That's a crazy place for it to be, right?
* It stopped checking for updates. Even though that option remained checked it never did. I had to manually download and install.
* Today it got into a crazy state where git from the command line and sourcetree disagreed about the status of my repo.
*In order to start fresh I uninstalled, then deleted AppData/Atlassian and AppData/Sourcetree. Then I re-installed, but it still remembered all my old git passwords. I had wanted to get rid of them.