PXE client computers freeze during multithread network transfers in Windows Server 2012 R2

Applies to: Windows Server 2012 R2 DatacenterWindows Server 2012 R2 StandardWindows Server 2012 R2 Essentials More


When you deploy Windows Server 2012 R2 through Windows Deployment Services (WDS) Pre-Boot Execution Environment (PXE), the server CPU usage spikes to 100%. In this situation, client computers may freeze while waiting for a response from the PXE server. 


This issue occurs because of a race condition on the server that occurs in PXE operations that attempt multi-threaded network transfers. For example:
  • A high number of logical processors (32+ logical processors)
  • Multiple clients connect to a single PXE 


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.


Learn about the terminology that Microsoft uses to describe software updates.