The WinRT programming environment, which is used to create Metro applications for Windows 8, replaces the old Win32 threading APIs such as CreateThread with a new ThreadPool::RunAsync API. This is generally a good thing (ThreadPool is better than CreateThread for several reasons) but it can be a pain when trying to port existing code that depends on those older APIs.
Porting shim to the rescue! This code emulates a subset of the Win32 threading APIs as a wrapper on top of WinRT ThreadPool:

• CreateThread
  
• CREATE_SUSPENDED and ResumeThread
  
• Partial support for SetThreadPriority (see comments in the header for details)
  
• Sleep
  
• Thread local storage (TlsAlloc, TlsFree, TlsGetValue, TlsSetValue, plus see header comments about TlsShutdown)
  
  Get it here: ThreadEmulation.zip
  I recommend only using this for porting legacy code. When writing new Metro applications, it is better to directly use WinRT ThreadPool.
  
  Source