Blender and keyboard

I have a problem with Blender (v2.72.3)
The keyboard doesn’t work inside the program.
All keys don’t work.
The mouse works correctly.
I have reinstalled the program but the problem persist.

What’s the problem? Can you help me?

I have Windows 8.1 64bit with Kasperky Antivirus 2015, Comodo Firewall 8, Antilogger Free and Malwarebytes Anti-Exploit.
Blender is in the exceptions of all security programs.
The keyboard is the Corsair Vengeance K70. It doesn’t require driver.

Thanks for your helpfulness.