Microsofts Developer Pete has pointed this:
In Windows 10, the Multimedia Class Scheduler Service was moved from user-mode to kernel-mode, to reduce overhead and improve integration with the kernel thread scheduler.
As a side effect, a per-process limitation of 32 registered threads was introduced. Applications which register a large number of threads in a single process may see MMCSS registration fail in Windows 10, in circumstances where it succeeded in Windows Vista through Windows 8.1.
We are looking at how to address this.
In general, Microsoft recommends the following for developers:
- Prefer using the Windows Real-Time Work Queue API Real-Time Work Queue API (Windows) over manually maintaining a set of dedicated threads.
- Be prepared for MMCSS registration to fail, since MMCSS resources will vary from system to system, and from even from time to time, depending on what other applications on the system are doing.
but Pete linked this Text from password protected Forum (Windows Insiders Developers ), i cannot see in.