Is it a new disc, or were you able to play it before? maybe there's a little scratch on the disc which the installation setup doesn't notice while installing.

I played it on my 'very' old PC, and the only problem i had then, was that it would crash after about 1-2 hours of playing, but this was on an old machine and happend with a lot of games of mine.

Did you check the warcraft/blizzard forum? maybe someone else had the same problem.

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