Hiya, As stated above that sounds like your keyboard is on the way out, replace it with another to test this.
If you desperately need to use your computer and you dont have a spare keyboard you can get anytime soon, consider using the onscreen keyboard in windows. it is located in your start menu, click Start - All Programs - Accessories - Ease of Use - On screen keyboard. this is slow and you will have to use your mouse to click the keys, but if you desperately need access to your computer, it is useable.