Were talking what easily below 7 at times. god knows what it hit during the night. shrugs moved the pc (and me!) back to somewhere warmer in the house and everythings been find since (fingers crossed!) thought the xbox is still having the odd issue but that was from day one so may not have been 'me' ><

In a room with an even remotely comfortable temperature that's impossible, and even with temperatures lower than that, that wouldn't happen unless a connector wasn't attached properly or a conductor had a hair-line crack.

On the topic of weird computer problems, my favourite WTF?-moment was the following: Years ago my old PC was suddenly unable to find any optical drive. DVD drive, CD burner, they were just gone from the OS. Nothing worked, there was no trace of them in the device manager, detecting new hardware got no results, all cables and connections were fine and both drives were detected without problem in the BIOS. I could even use them as boot devices. But as soon as XP booted up, they disappeared.

I spent days trying everything I could think of, checking cables and connections, using every piece of diagnostic software I could find, even re-installing XP several times from the very devices my OS insisted didn't exist...to no avail. The first time the OS proper booted up they were gone.

Finally, in a last ditch effort I reset my BIOS to standard values, despite all evidence that the BIOS worked just fine. After all, as long as the BIOS was in charge the drives worked like a charm. So I reset it, booted up windows...and they were back. Which in turn sent me on an epic quest to find out what BIOS entry exactly was responsible for this strange behaviour. Lots of tedious trial&error ensued.

In the end it turned out that a security feature in the BIOS was the culprit. There was an option to set a maximum CPU temperature that, once reached, would trigger the BIOS to perform an emergency shutdown. That caused the optical drives to vanish from the OS. Don't ask me why or how that was even possible, given that both things had nothing at all to do with each other. Whatever caused it, it was reproducible. As soon as I activated that option by entering any temperature value, *poof* the optical drives did a vanishing act. Days (or maybe weeks) before my trouble started, I had set a value there and then completely forgotten about it. And since apparently I hadn't used my optical drives since, I hadn't noticed the strange side effect.

Try making that connection without extensive trial&error or sheer dumb luck.

Are you sure that was the culprit? There was actually a registry edit (removing upper and lower filters) you could make to clear that error in windows. Check the Let me Fix it myself option below.
Microsoft Support on missing CD

Yes. As I said, the behaviour was reproducible.

Your link describes a different problem. Especially since the drives worked beforehand and therefore should have done so again after installing an original pre-ServicePack Windows XP.