Logitech ex100 driver corrupted - Logitech EX100 967499-0403 Keyboard

Try to Update your driver may it will work for you here are the easiest step for updating the drivers:

On Desktop
Right click on My computer icon and select Properties
Click on Device Manager
(Or follow Start button --> Control Panel --> Device Manager)

Now search for your hardware whom you want to update.
Right click on it and click on Update Driver Software...

It will ask for CD or DVD then insert the driver CD/DVD if you don't have then it will ask for searching the drivers over internet click Yes for it and it will automatically download the drivers for you.

Or you can use Third party software which can search,Download and Update them for you without making much effort.

Click here for Driver Updating Free Software's

Thank You...