Keyboard keys not working (Dell Inspiron)

I have a Dell Inspiron 1545 with Windows 7 and a majority of the top keys on the keyboard aren't working; more specifically the Q-R, and the U-P keys. I've had the computer for about 2 years now. I've had a previous keyboard issue in the past where I would type a the "I" key and it would type both the "I" and "O," but this was usually fixed by just restarting my computer. 

I've tried the keyboard troubleshooting procedure, but that didn't solve anything. I'm considering buying a new keyboard for my laptop but I don't want to waste the money if it is an issue with wiring and not the keyboard itself. Does anybody have any clue on how to fix or test my issue?