After I installed Kaspersky years ago against keys on the keyboard no longer - now another operating system is on top and the problem persists.
In the repair, they insert new buttons or fix the problem.
Kaspersky is an antivir. This has nothing to do with your keyboard.
Which keys have the problem?
Depending on the age of the device:
give for repair or
suitable for the model! Get the keyboard (available in the bay) and exchange it yourself