Windows 2000 Application Support
Applications that run out the normal Windows 2000 environment are supported with virtual machines. The following virtual machines are used:
- DOS VDM (Virtual Dos Machine) - Three threads - One used for applications and the other two are used to run the VDM. The files autoexec.nt and config.nt are used to setup the DOS environment rather than the autoexec.bat and config.sys files used traditionally with the original DOS operating system. These files are stored in the System Root\System32 directory.
- Win16 is used to support applications that ran on Windows 3.x and WFW. This is also called WOW which refers to the fact that Windows 16 bit applications run on the Windows 32 bit environment. Windows 16 bit applications are supported so long as they do not make direct calls to the hardware. All applications run on a single Win16VDM by default. There is no pre-emptive multitasking. These applications can be run on separate Win16 virtual machines if required.
- POSIX - The system must run on an NTFS filesystem to support POSIX applications. This is because POSIX requires user file permission support and security that is not provided by FAT filesystems. Each POSIX application runs in its own separate memory.
- OS/2 - Text OS/2 version 1.x is supported. There is no support for 2.x, 3.x, and presentation manager.