2.1 The Operating Environment

The operating environment for 386 enhanced-mode Windows consists of a computer's hardware devices and the following software components:

Virtual machine manager (WIN386.EXE)

Virtual devices (WIN386.EXE and .386 files)

ROM BIOS

MS-DOS

MS-DOS installable device drivers and TSRs, such as extended memory managers, network software, and disk cache software

Windows dynamic-link libraries, such as KRNL386.EXE, USER.EXE, and GDI.EXE

Windows and non-Windows applications

The virtual machine manager forms the core of this operating environment. It provides the service functions (also called services) needed to create and manage the virtual machines in which Windows and non-Windows applications run. The virtual devices support the device-independent VMM by managing the computer's hardware devices and supporting software. The ROM BIOS, MS-DOS, MS-DOS device drivers, and TSRs provide device-specific routines and operating system functions that applications use to indirectly access the hardware devices. Virtual devices manage this software as well as the hardware devices to ensure that no application disrupts the operation of another. The Windows dynamic-link libraries provide the functions and graphical resources that all Windows applications use.