Did i broke my board?

Hay all,

I like to know iff i broke my Arduino uno rev3 board. Because i did something stupide by putting 12v DC on the 5v pin. Is it possible to destroy it by putting 12v dc on the 5v pin? Because i can't connect it anymore with my pc. Used Linux and Windows In the Arduino ide selecting com poort is grayed out. Also when connecting with Windows nothing in device manager that' will refer to the board alsof no Windows bling sound.

Regards

The board has it owns defence. It should be working property even on 12V DC.

(deleted)

Thanks already for the fast replays. So this thing is broken or something is damaged!