I faced this issue on windows 7 home edition where the user was not able to press any key from keyboard more than once. If the user has pressed the “a” and like to press again he/she has to press some other key and then he/she will be able to press the “a” again.
There is a functionality in windows 7 that if you press the shift or any other key more than once in a very short time. It gives you option to stop this to prevent some damage to the system.
It can enable the “Turn on Filter Keys” in windows 7 which leads to the above issue. To solve this issue please follow the simple steps given below.
Go to Start Menu of Windows 7
Enter “Ease of Access” in the search bar and press enter
Ease of Access center will be opened.
Go to make the keyboard easier to use
Go to Turn on Filter Keys
Uncheck the check box to resolve this issue.