Well tell me How many times you accidently turned of CAPS LOCK key and then wrote a paragraph Or you were login in to your Bank Account Or some other and keep getting error that password is wrong and then realize that Caps Lock was on and your password is not in caps.
Well Caps Lock is the most least used key in the keyboard, Even Google has removed caps lock button from its notebook CR-48 and added Search button in its replace.
To disable Caps Lock key use this just download the ZIP file from below link and the extract and run Disable Caps Lock Key file, it will ask for a confirmation just confirm it and then restart your system to take this affect.
There is also another file, if in future you want your caps lock key back then just run that Enable Caps Lock Key file.