Virtual desktops help you keep open programs organized by putting each one into a separate virtual space. You can have your Web browser and e-mail in one desktop, and then switch to another that holds your word processing windows, for instance.
The free WindowsPager provides four such virtual desktops. The simple app doesn't require installation; just unzip the download and double-click the program inside the "exe" folder.
When you do, you'll see a preview of each virtual desktop on your taskbar that displays each desktop's open windows. You can move windows between desktops by right-clicking a program and choosing among new "Move to Desktop X" selections, or by holding CTRL and moving windows among the taskbar previews. To jump from desktop to desktop, click the preview for that desktop, or by holding CTRL and typing that desktop's number (1-4) on the number pad.
A couple of other options accessible by right-clicking a program's title bar allow for making a program window visible in all desktops, or keeping it on top of other windows.
WindowsPager is free and dead simple to use, but it lacks any way to change program options. You can't change the hotkeys for switching between desktops, or to use fewer virtual desktops, for example. But if you want an easy tool for using virtual desktops on your Windows PC, and you don't feel like shelling out the $20 for a more polished commercial tool (such as Actual Virtual Desktops), WindowsPager will take care of you.