USB booting :: Problem booting

Ok...

When i start the computer (my usb stick is plugged in),
it boots and then there's a screen telling me:
press enter to begin or F2 for boot options...
well...i press enter......again........again......
nothing happens.
Now the PC is on, and still it's there.
I tried pressing Num Lock, it doesn't respond, so i think it crashed.
Can you help me?

Hold the Power button for 10 seconds until it turns OFF.
If that doesn't work, pull the plug.
Then remove your USB stick.
Go to the manufacturer's web site and find the latest BIOS version for your computer model or for your motherboard model if it is a homebuilt system.
Install the new BIOS version.

Try again.

original here.