I'm really panicing right now.
I had over 2000$ in my offline wallet (Multibit) on my PC and it won't turn on. What should I do??
You didn't answer below, but what kind of PC is this? Some generic Windows machine? Mac? What OS? What exactly does it do when you try to turn it on? Absolutely nothing? Beep? Fans?
If you are running a Mac, you can use target disk mode
The odds are (as others have said) that you can recover it.