How can I force my machine to use only the first processor?

A. If you want to use only one processor of a multiprocessor machine, you can use the numproc boot.ini switch (see What switches can be used in boot.ini? for more information about numproc and other boot.ini switches).

1. Start a command session (Start, Run, cmd.exe).
2. Go to the root of the C drive.
3. Use the following command to modify the boot.ini file so it is not a system file, not hidden, and not read-only:
   
   

   C:\> attrib boot.ini -r -s -h
   

4. Open the file in Notepad:
   
   

   C:\> notepad boot.ini 
   

5. Locate the entry that starts the OS and add /numproc=1 to the end. For example,
   
   

   multi(0)disk(0)rdisk(0)partition(1)\WINNT="Microsoft Windows 2000
   Professional" /fastdetect /numproc=1
   

6. Save the change and exit Notepad.
7. Use the following command to reset the boot.ini attributes:
   
   

   C:\> attrib boot.ini +r +s +h