Hi Friend,
You have 2 options:
1. reinstall NT so that it can detect the new processor and install the multi-cpu kernels accordingly.
2. Or if you can get your hands on the following files from a multi-cpu system, you can write them over the existing files under DOS into WINNT\SYSTEM32
Ntoskrnl.exe
Winsrv.dll
Hal.dll
Kernel32.dll
Ntdll.dll
Win32k.sys
Yeah, Baby!
AP