This is about my brothers computer.

After about an hour or two of playing Heroes of Might and Magic 3, the game will lock up and the computer will freeze.

It only happens with this game (to my knowledge) and has only started happening recently. The thing that bugs me though is when I reboot and start up fresh, it gives me this message when loading up (At the Windows XP screen, the screen after the screen with the animated little blue loading bar).

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User Envirement
Windows can't load the users profile, but has logged you on with the default profile for the system.

Detail - The configuration registry database is corrupt
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Everything else about the computer is fine. Can use it for hours. It's only when playing this one game. OS is Windows XP professional (legit copy).

I ran windows update last night and will see if that fixed anything. As you can imagine, having the only identifiable wrong thing be the game freezing up the comp after an hour or two kinda makes it hard to tell if you've fixed it or not.

I did a search for that message on The Google but only came up with one page that was in some form of german I think, and I don't have the time to run it through babelfish to figure out which one it really is.

Anyways, heading over there to see if running Windows update fixed anything. One of the updates mentioned games hanging, but it was "when playing introductory video."

After about an hour or two of playing Heroes of Might and Magic 3, the game will lock up and the computer will freeze.

Older games use software rendering to do most of the work when displaying images.

This also means that a lot of load goes into the CPU instead of the GPU where it belongs. Sounds like it's overheating.(Hard lock, control alt delete won't reboot it)

If he is running a Raid Stripe, that could cause corruption also, I remember hearing about an issue with abit cards. I'd flash the BIOS to the latest version as well.

Another thing it could be is flaky memory, values getting pulled from the registry, and rewritten with values that aren't correct.(Make sure the ECC function is on/off, depending on type of RAM, and that the memory is running at spec, not overclocked)

Those are some of the first things I'd look at.

If you have the original edition of HoMM3, patch it or install Armageddon's Blade/Shadow of Death for the update. I remember the initial release being pretty buggy.