Webopedia on Google+Webopedia on TwitterWebopedia on FacebookTech Bytes Blog
Main » TERM » N »

NTVDM

The 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.







TECH RESOURCES FROM OUR PARTNERS
DID YOU KNOW?
It's Happening Now: Perceptual Computing is Real

Perceptual computing is the ability for a computer to recognize what is going on around it. More specifically, the computer can perceive the... Read More »

Apple Pay Promises to Strengthen Payment Security

Experts believe that Apple Pay and other competitive payment systems will be far more secure than cards, even cards equipped with EMV chips. Read More »

The Great Data Storage Debate: Is Tape Dead?

Tape clearly is on the decline. But remember, legacy systems can hang for a shockingly long time. Read More »

QUICK REFERENCE
Network Fundamentals Study Guide

A network is a group of two or more computer systems or devices, linked together to share resources, exchange files and electronic communications.... Read More »

Computer Architecture Study Guide

This Webopedia  study guide describes the different parts of a computer system and their relations. Read More »

Webopedia Polls

The trend for the past two years has been for shoppers to spend more online during the holiday season. How do you typically shop for holiday... Read More »