Limiting number of Cores using msconfig

I want to down core machine(PC) using application or driver.

• I've tried using msconfig ,user can limit number of core he wanted to be enabled.
• When selecting option msconfig -> Boot -> Advanced Option -> Number of processor, drop down list.

• But every processor(Intel , AMD,..etc) having different hardware architecture. Still using msconfig , user can able to limit number of cores.

  1. Want to know how msconfig is handling this functionality?
  2. Is that tool writing into any CPU register?
  3. Or any Windows API to do the same?

Please share your thoughts.

1. Windows uses HAL (Hardware Abstraction Layer), which allows all its components to work the same way with the different hardware. Specifics are handled by the hardware device drivers.

2. CPU registers are used by processor when it is executes a code. There are many kinds of registers, they all are described in the processor developer specification. While msconfig of course using CPU registers, it just a configuration tool. Also you should understand, that each process has its own register state structure called CONTEXT, so it is unclear what exactly you are trying to achieve.

3. msconfig just saves a configuration information, which is used by Windows kernel, so it could limit CPU cores/memory on initialization. You could limit available processors for the selected process using API function SetProcessAffinityMask.