Virtuoz is a very small, simple and lightweight tool for managing multiple virtual desktops.
The program is tiny, with no installation required - just launch it and Virtuoz runs in the background, with no visible interface other than a new icon in your system tray.
By default Virtuoz supports four desktops. If your current desktop is cluttered, you can switch to another by right-clicking the system tray icon and selecting it from the list, or by pressing the appropriate hotkey (Alt+1, Alt+2, Alt+3, Alt+4).
There's also a hotkey to move the currently selected window from one desktop to another. By default this is supposed to be Alt+~ , although it may vary depending on your keyboard layout (on our system it was Alt + ').
If you have any concerns with the default hotkeys then they can be changed, at least in theory. There's no interface for this, though - you have to edit an INI file - and it didn't appear to make any difference to the "move window" hotkey.
You can also change the number of supported desktops to anything from 2 to 20 by editing another INI file value.
Virtuoz is just about as basic as a virtual desktop program can get. It's also extremely simple and lightweight, though, and if the "move window" hotkey works for you then it might appeal.