Got it. But how do I fix this problem of double key strokes coming up repeatedly?

[work.bombay]

I have been facing the problem of multiple characters being typed with one key stroke when i enter password to access windows.

 

[Saga Lout]

Use the onscreen keyboard for password input because if you foul it up three times, Windows can spit its dummy out of the pram.

As to the keyboard, toast crumbs and cat fur are the usual suspects. Turn the laptop upside down while open and lean it against your shoulder then smack its backside as you would if burping your baby. It's amazing the rubbish falls to the ground.