Boot Selector Hanging

Hi everyone, hope someone can help me with this. First off I love Windows 7, and loved Vista too.

Here's my problem, I have been trying to used the boot selector on the start up. Hitting F12 in my case, not sure if it differs on other peoples computers. It was working fine, but now when ever I do it the computer just hangs on the screen. The fan starts to get really loud as well. I don't have anything plugged into the computer, and I only have one OS installed on my computer. Anyone know what's going on, I can only think that maybe a file has got corrupted or there's something wrong with my bios.

If I go in to setup, it will list all the boot able drives...but obviously wont let me load from there. So why if it has no trouble here, does it not even load on the boot select option. Many thanks to anyone that can help, this has become a real pain.

Hi thanks very much. Yes that's right, left on its own the default OS boots fine. Just when I hit F12 at the start, it hangs. I'll try updating the bios and see how things go.

Hey just installed the updated bios, everything went well and windows restated and loaded again fine. However when I shut it down, and turned it on again to try the bios select the same thing happened. The computer hangs, and fan gets really noisy. But if I hit Esc then it shows some system information and then starts Windows as normal, I think this worked before I updated the bios as well. Any ideas what else it could be? Many thanks.

Any ideas?