Sysinternals Desktops v1.0 allows you to create up to four virtual desktops and to organize your applications on the different desktops. Browse the web on one desktop, read your e-mail on a second desktop and organize your work applications (Word, Excel, Photoshop, etc.) on another desktop.
You can easily switch between the different desktops using the tray icon with preview or using configurable hotkeys.

What makes Desktops different from other virtual desktop applications is the way it has been implemented. Desktops uses a separate Windows desktop object, running its own explorer.exe instance, for each desktop, rather than faking virtual desktops by hiding applications.
Application windows are bound to one desktop object when they are created. This approach has some advantages and disadvantages:

Advantages:
- Desktops is lightweight and very fast
- Desktops actually works and seems bugfree. All other tools I've tried had issues with inconsistencies between desktops (application windows showing up on the wrong desktop, etc.)
- No installation required. Desktops can be run from a USB key.

Disadvantages:
- Applications cannot be moved from one desktop to another
- Most tray icons are only visible on the first desktop
- Switching between applications using Alt+Tab only works on the first desktop
- The same desktop background for all desktops
- Vista Aero is only available on the first desktop


Although the list of disadvantages is longer than the list of advantages, Sysinternals Desktops v1.0 is one impressive tool. But I didn't expect anything else from Sysinternals.
It is lightweight, fast, reliable and easy to use. Make sure to give it a try. You'll be impressed!

One remark:
If you use Comodo Firewall Pro with Defense+, make sure to add Desktops as a trusted application BEFORE creating a second desktop or you will end up with a deadlock situation: Desktops will try to create a new desktop, but Comodo blocks this attempt on the first desktop.

Sysinternals Desktops runs on Windows Vista SP1 and Windows XP SP3.
You can download Sysinternals Desktops here.

Courtesy : http://technet.microsoft.com/