HTC EVO 4G stuck on HTC screen with 4 exclamation points

[dv220s]

Hi everyone. As the title says, my friend's EVO is not booting up. It's giving me the 4 exclamation points in the 4 corners with an HTC logo in the middle. I can't do anything else, no volume down and power as it does nothing. I have tried hooking up to the PC but the PC makes the sound like it recognizes it and but nothing happens.

Please help!