(Windows only) On Windows, the Web Server supports both kernel-level and user-level threads. User threads are scheduled by Netscape Portable Runtime (NSPR) within the process, whereas kernel threads are scheduled by the host's operating system. Usually, the standard debugger and compiler are intended for use with kernel-level threads.
If you set KernelThreads to 1 (on), the server uses the kernel-level threads. If you set KernelThreads to 0 (off), the server uses the user-level threads, which might improve performance.
where value is 0 or 1.