Unusual start-up problem

[lumis]

So a friend of mine brought his box over, it was infested with spyware, running slow, etc, etc. So I pulled the HDD, put it in my PC backedup all his documents.. I then popped the HDD back in his box, formatted & installed xp pro (w/ sp2), installed the first wave of updates, attempted to reboot and it just kept hanging on the loading screen (black screen, windows logo, scrolling bar). So I booted in to safe mode, no problems, but it still wouldn't let me back in to normal mode no matter what. So I ran a recovery console & ran fixmbr & fixboot, rebooted and tada, it lets me back in.. But everytime I restart the computer after that I encounter the same "hanging" issue at the start-up screen. The solution I came up with was;

Boot in to safe mode, restart computer and boot off xp cd, run recovery console, fixmbr & fixboot, boot normally.

But it's not much of a solution. I've tried running an sfc /scannow, nothing came up fishy.

Very unusual.

[redwudz]

Did you repartition first before formatting? The only other thing that comes to mind is a problem with the hard drive.

Did you try to reboot right after the XP install? Though, with the install there should have been a couple of reboots. I'm wondering since it boots in safe mode, if you installed a driver it didn't like with the updates, and that doesn't load while in safe mode?

[lumis]

Okay after a bit more of investigating I've discovered something kind of weird. For some reason when it's booting in to windows (or attempting to) the NUM LOCK & CAPS LOCK (which I turned on) go off and they can't be turned back on. Weird.

[lumis]

Turns out it was a crapped out modem causing this weirdness.

Thanks for the suggestion redwudz.