Q:

How to get the name of the select wallpaper

How can I get the name of the current desktop wallpaper in Windows, using C#?

A:

Something like this?
var wpReg = Registry.CurrentUser.OpenSubKey( "Control Panel\\Desktop", false );
var wallpaperPath = wpReg.GetValue( "WallPaper" ).ToString();
wpReg.Close();

From the path you can extract the filename ...

A:

Based on @tanascius's answer, I came up with this code.
Windows 7:
var wpReg = Registry.CurrentUser.OpenSubKey("Software\\Microsoft\\Internet Explorer\\Desktop\\General\\", false);
var wallpaperPath = wpReg.GetValue("WallpaperSource").ToString();
wpReg.Close();

Windows XP:
var wpReg = Registry.CurrentUser.OpenSubKey("Control Panel\\Desktop", false);
var wallpaperPath = wpReg.GetValue("WallPaper").ToString();
wpReg.Close();

