However, once your virtual machine is up and running, you then have to install an operating system on it! That is just like installing an operating system on real hardware. As long as your virtual machine has access to a CD-ROM, simply place the install CD into your system's CD-ROM and power up your virtual machine (that is, click on the power button). Your virtual machine will run through the installation process and reboot at the end, just as Windows normally does.
In addition, VMware comes with a set of tools for each operating system that it supports. Those tools allow your virtual machine to gain high-speed access to the full display on your system instead of running in a window.
Because VMware provides a virtual machine, it is not restricted to running Windows. You can run quite a large number of operating systems under VMware, including MS-DOS, Windows 9x, Windows NT, Windows 2000, FreeBSD, and Linux. Thus, VMware is ideal for testing out new operating systems, providing a teaching environment, or grabbing screen shots of installation.
I also found the number of ways you can use VMware to be astounding. The Samba team uses it to test out changes to Samba by simply running Win NT in a virtual machine. I have used it to develop courses that deal with the installation of operating systems, including the booting phases, because I can very easily grab screen shots without the need for a digital camera. Also, if you run those virtual machines out of a virtual disk (a file in your file system) instead of a partition, it is very easy to copy your virtual machine to another system or keep backups.
The current version of VMware is 2.0.2, and it runs on all versions of Linux, including SMP systems, and on Windows NT and Windows 2000. It is priced at USD299 for commercial use and USD99 for hobbyist and student use. You can download it from the VMware Website. However, one of the things you will notice with VMware is that it requires more resources than Wine or Win4Lin. For example, a VMware virtual machine running on a 400 MHz Pentium II will feel like a real machine running at around 200 MHz to 266 MHz.
Bochs, according to the Website, "is a highly portable x86 PC emulator written in C++ that runs on most popular platforms. It includes emulation of the Intel x86 CPU, common IO devices, and a custom BIOS. Currently, bochs can be compiled to emulate a 386, 486, or Pentium CPU. Bochs is capable of running most operating systems inside the emulation, including Linux, Windows 95, DOS, and recently Windows NT 4." It was developed by Kevin Lawton.
I have not downloaded or installed it, but mention it here as it may be an alternative for those running Linux on hardware other than Intel compatibles.