Microsoft, in all its blessed wisdom, decided to keep Windows wallpapers in the system directory. This can lead to stability and\or security issues (“I was trying to install a wallpaper of my kids at the lake, and I saw this folder called SYSTEM32 taking up a bunch of space, so I tried to delete it, and now my computer won’t boot!”). It can also make disk images needlessly large: because Windows does such a crappy job of using JPG images as wallpaper, I keep around 125MB of wallpapers in my own WINDOWS folder, along with a 300MB archive file of wallpapers not currently in use.
Wouldn’t it be nice if you could change the location that Windows looks in when you right-click on the desktop and choose Properties > Desktop? Well you can! Just fire up Regedit and go to the following key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion
Look for a string called WallPaperDir. The value will probably be at the default location – %SystemRoot%\Web\Wallpaper. Simply change this to whatever directory you want to use (perhaps F:\Wallpaper) and close Regedit. No reboot is needed – the next time you open the applet, Windows will look in the directory of your choosing!