Shift keys not working properly

Hello,

I have annoying issue with my keyboard. When I press the left shift key it writes 7. Right shift writes 2. I tries to type "When I" it is typed as "7When 2I". 7 and 2 are not repeated when the shift key is press and hold. I had to press the backspace key several times to delete 7s and 2s even while typing this.

It happens for all keyboard layouts. I have tried repairing windows. Still this crazy thing happens. I'm using windows7 ultimate edition on a Toshiba L655.

Please help me.