VirtuaWin - VirtuaWin is a virtual desktop manager for the Windows operating system (Win9x/ME/NT/Win2K/XP/Win2003/Vista/Win7/Win10). A virtual desktop manager lets you organize applications over several virtual desktops (also called 'workspaces').
Cairo Shell - Cairo is a desktop environment for Windows.
Dexpot - If you don't have Dexpot yet, the new update makes it a must-have tool for Windows, adding a ton of features to your desktop that you never knew you wanted.
Talisman Desktop - Talisman Desktop is a configurable Windows shell replacement introduced in 1997 by Lighttek...
9Desks - up to nine virtual desktops
bbLean - Alternative Windows shell