>I have a couple of custom-developed applications that I market in "shrink-wrap" fashion. The application anti-piracy system reads the Hardware ID from the Hard Drive in order to generate a serial number that is then matched to another number to unlock the application. The application is written in VFP 8 and Codemine 7.1.
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>All of a sudden, one of my own compputers started crashing on the apps for no reason. After looking around a bit, I discovered that it was generating a Hardware ID of F instead of the mandatory 6 numeric serial number - and thus the registration routine stopped working. This happened to an already functioning application on a computer that had previously not had this problem.
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>This problem had been reported by two users on different occasions but we dismissed them as "flukes". Now that its happened to me I'm taking it very seriously.
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>No hardware was changed on this computer of mine. It is running XP Home with SP1. Norton 2004. I have also used Sybot and Adaware.

Does disabling AV make any difference?

Have any recent critical updates been applied to Windows?