According to this:
http://support.microsoft.com/kb/168132"The Setup.log (found in the %SystemRoot%\Repair directory) was created when Windows NT was first installed and contains information about the files copied to your system during Windows NT setup. Consequently, the file reflects the information for a single processor computer. When service packs are installed, the Setup.log file is parsed looking for the correct Hal.dll and Ntoskrnl.exe to replace."
That is in response to adding CPU's to what was originally a single-CPU system and then running the utility Uptomp.exe from the Windows NT Resource Kit.
So basically the culprit responsible for downloading multi-processor kernel updates on my single-processor system is the setup.log file. Now how to modify it so that future microsoft updates are handled correctly?
From the above link:
RESOLUTION
By modifying the %SystemRoot%\Repair\Setup.log file, you can tell the service pack Update.exe program to load the correct multiprocessor components (thus taking you back to multiprocessor support and at the same time ensuring that future service packs install correctly).
[in my case, I want to modify it so that it reflects a uni-processor installation]
Steps to fix the Setup.log and restore your system to multiprocessors:
1. Remove the read only and hidden attributes on the %SystemRoot%\Repair\Setup.log file.
2. Make a backup copy of the %SystemRoot%\Repair\Setup.log.
3. Open the Setup.log using notepad.
4. Search for and modify the following lines, being careful to use the correct operating system version section and proper HAL for your computer type:
Windows NT version 4.0
Modify the entries under [Files.WinNt] section to the following:
\<%SystemRoot%>\System32\Ntoskrnl.exe = "NTKRNLMP.EXE","e76ab"
\<%SystemRoot%>\System32\Kernel32.dll = "KERNEL32.DLL","5b7f8"
\<%SystemRoot%>\System32\Winsrv.dll = "WINSRV.DLL","37b4e"
\<%SystemRoot%>\System32\Ntdll.dll = "NTDLL.DLL","59c19"
\<%SystemRoot%>\System32\win32k.sys = "WIN32K.SYS","132603"
Then, select one of the following HALs and modify the line:
\<%SystemRoot%>\System32\hal.dll = "HALSP.DLL","0f337"
\<%SystemRoot%>\System32\hal.dll = "HALMPS.DLL","1a01c"
Windows NT version 4.0 Terminal Server Edition
Modify the entries under [Files.WinNt] section to the following:
\<%SystemRoot%>\System32\Ntoskrnl.exe = "NTKRNLMP.EXE","fe754"
\<%SystemRoot%>\System32\Kernel32.dll = "KERNEL32.DLL","700ee"
\<%SystemRoot%>\System32\Winsrv.dll = "WINSRV.DLL","3e526"
\<%SystemRoot%>\System32\Ntdll.dll = "NTDLL.DLL","62b31"
\<%SystemRoot%>\System32\win32k.sys = "WIN32K.SYS","140e95"
Then select one of the following HALs and modify the line:
\<%SystemRoot%>\System32\hal.dll = "HALSP.DLL","15a34"
\<%SystemRoot%>\System32\hal.dll = "HALMPS.DLL","1a062"
5. Save the modified Setup.log to the %SystemRoot%\Repair directory.
6. Re-apply the service pack to take you back to MPS support.