http://freewisdoms.com/how-to-fix-vib...
http://freewisdoms.com/how-to-install...
Short and easy explanation on how to fix "Viber has stopped working" error, which may occur when you try to launch Viber.exe on Windows 7.
This problem is almost always related to outdated system files, so updating Windows 7 and installing Service Pack 1 is the best solution.
Follow the links above to check full tutorial for fixing this error and updating your system.