Wallpaper Engine - Wallpaper Engine enables you to use live wallpapers on your Windows desktop.
WinDirStat - WinDirStat is a disk usage statistics viewer and cleanup tool, inspired by KDirStat.
Lively Wallpaper - What is it? Lively is a Free and Open-Source Software (FOSS) for animated desktop wallpapers.
TreeSize - TreeSize tells you where precious disk space has gone to.
ScreenPlay - Open-source and cross-platform Wallpaper, Widgets and AppDrawer app.
SpaceSniffer - SpaceSniffer is a freeWare (donations are welcome) and portable tool application that lets you understand how folders and files are structured on your disks.