My Minecraft won't load up and it keeps crashing every time that I turn it on.

I was playing Minecraft, when all of a sudden the server crashed. After resetting my PC, I tried to go on again, but it still wouldn't work. I thought that it was my computer, so I disassembled it and reassembled it to see if Minecraft would work, but MInecraft still wouldn't work. It just says that the server has crashed.