Editing Virtual DOS machine (section)

===Limitations===
A limitation exists in the Windows XP 16-bit subsystem (but not in earlier versions of Windows NT) because of the raised per-session limit for GDI objects which causes GDI handles to be shifted to the right by two bits, when converting them from 32 to 16 bits.<ref name="XPVDM bug"/> As a result, the actual handle cannot be larger than 14 bits and consequently 16-bit applications that happen to be served a handle larger than 16384 by the GDI system crash and terminate with an error message.<ref name="XPVDM bug"/>

In general, VDM and similar technologies do not satisfactorily run most older DOS games on today's computers. Emulation is only provided for the most basic peripherals, often implemented incompletely{{Citation needed |date=April 2010}}. For example, sound emulation in NTVDM is very limited. NT-family versions of Windows only update the real screen a few times per second when a DOS program writes to it, and they do not emulate higher resolution graphics modes. Because software mostly runs native at the speed of the host CPU, all ''timing loops'' will expire prematurely. This either makes a game run much too fast or causes the software not even to notice the emulated hardware peripherals, because it does not wait long enough for an answer.