Solution:

In order to use WinNT 4.0 (or some other legacy OS) well with the main board for Prescott P4 CPU design, please go to CMOS setting to Enable "Limit CPUID MaxVal" feature. Per Intel's test result, legacy operating system, such as WinNT4.0, uses old CPU control programming. If loading such OS for the latest P4 CPU in Prescott core or newer one, OS may work abnormally with the CPU to cause the OS not bootable. Advantech's test result shows us that OS installation will halt after File System Converting from FAT to NTFS during installation stage. This causes the OS not bootable. In order to mask the physical CPUID for Proscott core when running WinNT, Award BIOS provides "Limit CPUID MaxVal" feature. Enabling this feature will make the main board BIOS respond "suitable", "virtual" CPUID to OS kernel. So WinNT or the legacy OS can use the masked CPUID to work well with the new CPU design. Please remember to Enable "Limit CPUID MaxVal" setting if you're running WinNT4.0 with newer main boards in P4 CPU structure. It is especially when you're using Prescott CPU with PCA-6187 and AIMB-742.