***EDIT: I'm terribly sorry. I don't know how to delete this. He had a Micro SD card in its adapter plugged into his computer. When he pulled it out, the computer booted up just fine. I don't know why. Thank you for your time.
My dad just went to update his HP Windows XP computer. I have no idea what any of the specs of his computer are, sorry, I just know that it's fairly old. A few years at least. As far as I'm aware, no routine maintenance is done on it, so any quick fix ideas, regardless of how simple, would be very appreciated. Of course, he's got all of his important stuff on there (years worth of stuff saved up, obviously), so we're willing to go through long fixes, too.
Basically, he was prompted to update, and he allowed the computer to restart itself. When it attempted to boot up, it got to the HP screen (the one where it shows you that you can press F1 or F10, etc.), and then it just completely froze up, but he waited a few minutes, to no avail. He tried pressing F8 to boot in Safe Mode after a few restarts, and nothing happened. It refuses to load anything at all. The lights on his computer turn on, they don't flash or anything...