1
Go into the keyboard settings and switch your keyboard form the US English International keyboard to just the US English keyboard, restart (not shut down) your PC and then go back into settings and set the keyboard language back to US English International keyboard.
2
If that does not resolve the problem:
Open Command Prompt, then paste in this command and press Enter:
msdt.exe -id KeyboardDiagnostic
Run that Keyboard Troubleshooter to see if that can solve the problem.