My keyboard can't do shortcuts

Hello,
Windows Vista was reinstalled in my computer by "computer specialist". When I got it home my keyboard does not recognize the "Ctrl" Key. I can't do any of this: paste, copy, select all.. and others. Before sending my computer to get Vista reinstalled my keyboard worked well, but know my keyboard does not do those shortcuts. I really need them, I'm a graphic designer and those shortcuts makes my life easier. I called the "computer specialist" and he told me that I had to buy a new keyboard. I don't think that's the solution because it was OK before. He made the installation with another keyboard. Please could someone tell me what can I do to fix this?. Thank you!!!