碰到一个需要修改桌面背景的需求，将解决方案分享，下面是通过vb写的（可以将如下代码放入一个html页面执行即可）

<script language=vbscript>
        document.write("11111")
        Sub changeWallPaper
           set ws = createobject("wscript.shell")
            document.write("2222")
           ws.regwrite "HKCU\Control Panel\Desktop\wallpaper","d:\deskTest\4.jpg","REG_SZ"
           ws.run "RunDll32.exe USER32.DLL,UpdatePerUserSystemParameters" 
           ws.run "D:\deskTest\refresh.bat"   
            document.write("3333")
        End Sub
        changeWallPaper
            document.write("4444")  
</script>

 
<img id=bgimg border="0" src="d:\deskTest\4.jpg">
<button id="btn" value="改变桌面背景" onclick="changeWallPaper">

D:\deskTest\refresh.bat这个文件是用来刷新桌面的批处理文件，由于修改注册表后不刷新桌面没法及时显示更新桌面图片，代码如下：

@echo off
if exist D:\deskTest\bak.jpg (del/q  D:\deskTest\bak.jpg)
if exist D:\deskTest\7.bmp (rename D:\deskTest\7.bmp bak.jpg)
RunDll32.exe USER32.DLL,UpdatePerUserSystemParameters
ASSOC .AV=AVFILE>NUL 2>NUL