The Desktop Heap Monitor is a tool that examines usage of desktop heap. The Win32 subsystem has an internal heap area known as the desktop heap. When you run a large number of Windows-based programs, an "Out Of Memory" error message may appear when you attempt to start new programs or try to use programs that are already running, even though you still have plenty of physical and pagefile memory available. This behavior can occur if the desktop heap in the WIN32 subsystem is depleted. By using the Desktop Heap Monitor, you can examine how much desktop heap is consumed without interrupting the running system.
Windows Server 2008