32-bit DOS emulation is used for DPMI and using 32-bit memory. wowexec.exe is the emulator process for 16-bit Windows. Windows 2000 added Sound Blaster 2.0 emulation to 32-bit NTVDM. 16-bit and DOS virtual device drivers can't be run. Win16 programs can communicate with other parts of Windows using OLE, DDE and named pipes.