NTVDMThe NT Virtual DOS Machine (a.k.a WOW, or Windows on Windows), is a Win16 subsystem that runs under Windows NT, which allows 16-bit applications to run as if they were being executed on a DOS machine, with that machine's multitasking and segmented memory model.
Because the system is multitasked 16-bit DOS and Windows applications cannot crash NT. However, 16-bit apps within a Win16 subsystem run the exact same way as they do on a DOS/Win 3.x machine; therefore, 16-bit apps within the subsystem can crash one another, or the subsystem. To prevent this, you can launch multiple WOW subsystems as long as your program does not communicate using shared memory.
Windows NT will not allow NTVDM to execute instructions that try to directly manipulate hardware or memory locations. As a result, some DOS and Windows 3.x applications (such as games) may not run under Windows NT.
Stay up to date on the latest developments in Internet terminology with a free weekly newsletter from Webopedia. Join to subscribe now.
From keyword analysis to backlinks and Google search engine algorithm updates, our search engine optimization glossary lists 85 SEO terms you need... Read More »Slideshow: History of Microsoft Operating Systems
Microsoft Windows is a family of operating systems for personal computers. In this article we look at the history of Microsoft operating... Read More »Slideshow: Interesting Facts About Google Search
From Goats to Penguins, a server outage and trillions of searches, our slideshow presents interesting facts about Google and the Google.com... Read More »
Java is a high-level programming language. This guide describes the basics of Java, providing an overview of syntax, variables, data types and... Read More »Java Basics, Part 2
This second Study Guide describes the basics of Java, providing an overview of operators, modifiers and control Structures. Read More »The 7 Layers of the OSI Model
The Open System Interconnection (OSI) model defines a networking framework to implement protocols in seven layers. Use this handy guide to compare... Read More »