If GitHub for Windows crashes, one of the most useful things you can do is send us a "crash dump". The dump records the state of the program at the time it crashed. Here's how you can get a dump to send to us. Once you have the dump file, zip it and upload it to Dropbox, Google Drive, or a similar service, then send us the link.
Windows Vista or newer
By default, Windows uploads crash dumps to Microsoft, but does not save a local copy. To enable saving of crash dumps so that you can attach them to issues, save this file, double-click it, and respond affirmatively to any prompts.
The next time GitHub for Windows (or any other application) crashes, the crash information will be written to a file with a name like:
%LOCALAPPDATA%\CrashDumps\GitHub.exe.NNNN.dmp
.