Why Would the Left Shift Key Stop Working For "E, C ,N and @"? Right Shift Key Works Fine.

[eatmetoyota]

To be more descriptive, I can no longer type an uppercase E, uppercase C, uppercase N or the '@' using the left SHIFT key. The right SHIFT key works fine. All four of these anomalies occurred at the same time as I was writing an email. The keyboard is a wireless Logitech keyboard mouse combo. I plugged in a $4 cheap USB corded keyboard and it works fine. This one has me scratching my head.

 

[eatmetoyota]

After running a system restore, the calculator app was launched 20 times revealing that the quick launch key was stuck. No clue why calculator app didn't launch before the system restore. All 4 keys work now with the left shift key.