August 27th, 2004
Microsoft recommends uninstalling SP2 to some AMD users
According to a recently published article in Microsoft’s on-line Knowledge Base (KB), the hardware-enforced "no-execute" (NX) buffer-overflow protection that SP2 introduced to Windows XP – known as Data Execution Prevention (DEP) — has caught its first offender and it’s a legitimate piece of software (a driver, in this case). Though such incompatibilities weren’t unexpected and can usually be overcome (see below), the resulting behavior on afflicted systems goes a bit beyond what Microsoft says will happen if a DEP violation is detected and, worse, the only guaranteed fix in this case is to uninstall SP2. Normally, according to Microsoft, DEP offending applications will crash and the user will receive an error message explaining why. But in this case, the computer just continually restarts itself. Also, in most situations, users and systems administrators can set DEP to be bypassed for legitimate applications and drivers with known compatibility problems. But in this case, the Microsoft KB entry says doing so "may" solve the problem and that "To work around this issue, remove Windows XP SP2 from your computer."
For you to be affected by the problem, you need to be running Windows XP SP2 on an AMD64-based processor in a hardware configuration that requires the mpegport.sys file to be loaded (I’m still trying to hunt down what this is for.. if you know, write me). Intel-based Windows XP machines are not affected because they lack support for hardware-enforced NX protection. It’s a shortcoming that led me to recommend holding off on the purchase of Intel machines until Intel corrects the situation. That recommendation still stands by the way. The problem doesn’t affect all AMD64-based users (only those with that specific driver running). The fix will most definitely be a software issue (as will the fixes to other, so far unreported DEP-incompatibilities) and my guess is that it won’t be long until we see it.
