I’ve run into this issue before. When I double click on the openhab start.bat file in a Windows 7 machine, I get this quick cmd window and it disappears instead of staying and starting OpenHAB. I’ve never figured out how to fix it.
Try to start the start.bat from commandline, maybe there is a message when starting openHAB fails.
To do this, start cmd.exe and navigate to the openHAB runtime folder.