I've stopped IIS and SQL Server Reporting Services and the GitStack install STILL complains about port 80.
I downloaded TCPView and the only HTTP processes listening are System(PID=4) and TCPView kill doesn't seem to have any ability to actually kill the system (not sure if it even should).
Any ideas? The GitStack.com WordPress Q/A isn't letting me post a question directly on that site.
solution:
Launch RegEdit
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\HTTP
Change the value of "start" to 4 (disabled)
Reboot your computer