If I manually change the background image in the registry, how can I force it to refresh without logging off?

I know that bginfo does it, but I would like to keep things simple and not use any software.

RUNDLL32.EXE USER32.DLL,UpdatePerUserSystemParameters 1, True
  • 7
    This doesn't seem to work in win7 x64... anyone have something that works for that? – Jon Marnock Apr 29 '14 at 1:50
  • 3
    Using it as RUNDLL32.EXE USER32.DLL,UpdatePerUserSystemParameters 1, True seems to work on my machine (note the missing comma behind UpdatePerUserSystemParameters) – Nebula Aug 11 '15 at 9:28
  • Can confirm, doesn't actually refresh the desktop on Win7 x64. Tried calling both versions of RunDll just in case. – Scott Solmer Oct 12 '17 at 16:45
  • Open Task manager
  • Kill explorer.exe
  • If the shell doesn't immediately restart
  • From the menu select File > New Task
  • Type "explorer.exe" and hit enter.
  • Good thought, but that simply doesn't solve it. – Nathan Strutz Sep 3 '15 at 14:01

I was trying to do something similar - update a registry setting for the start menu and then immediately have the start menu reflect the changes.

The solution from this MSDN question worked for me perfectly.

You could try broadcasting a WM_SETTINGCHANGE message. For example:

class Program
    [DllImport("user32.dll", SetLastError = true)]
    private static extern IntPtr SendMessageTimeout(IntPtr hWnd, int Msg, IntPtr wParam, string lParam, uint fuFlags, uint uTimeout, IntPtr lpdwResult);

    private static readonly IntPtr HWND_BROADCAST = new IntPtr(0xffff);
    private const int WM_SETTINGCHANGE = 0x1a;
    private const int SMTO_ABORTIFHUNG = 0x0002;

    static void Main(string[] args)
        SendMessageTimeout(HWND_BROADCAST, WM_SETTINGCHANGE, IntPtr.Zero, null, SMTO_ABORTIFHUNG, 100, IntPtr.Zero);

Change the screen resolution, then choose the revert option. Your resolution will remain the same and the background will have changed.

Alternatively, disconnect and reconnect the display cable.

  • This solution should have more votes. It works reliably and doesn't require any scripting. – Paul Russell Aug 6 '20 at 9:24
# first in powershell, second both. cmd.exe + powershell.exe

# Refresh Desktop Ability
$definition = @'
    private static extern int SHChangeNotify(int eventId, int flags, IntPtr item1, IntPtr item2);
    public static void Refresh() {
        SHChangeNotify(0x8000000, 0x1000, IntPtr.Zero, IntPtr.Zero);    
Add-Type -MemberDefinition $definition -Namespace WinAPI -Name Explorer

# Set Safe within deleted days and get physical drive letters
$ignoreDeletedWithinDays = 2
$drives = (gwmi -Class Win32_LogicalDisk | ? {$_.drivetype -eq 3}).deviceid

# Process discovered drives
$drives | % {$drive = $_
    gci -Path ($drive+'\$Recycle.Bin\*\$I*') -Recurse -Force | ? {($_.LastWriteTime -lt [datetime]::Now.AddDays(-$ignoreDeletedWithinDays)) -and ($_.name -like "`$*.*")} | % {

        # Just a few calcs
        $infoFile         = $_
        $originalFile     = gi ($drive+"\`$Recycle.Bin\*\`$R$($infoFile.Name.Substring(2))") -Force
        $originalLocation = [regex]::match([string](gc $infoFile.FullName -Force -Encoding Unicode),($drive+'[^<>:"/|?*]+\.[\w\-_\+]+')).Value
        $deletedDate      = $infoFile.LastWriteTime
        $sid              = $infoFile.FullName.split('\') | ? {$_ -like "S-1-5*"}
        $user             = try{(gpv "HKLM:\Software\Microsoft\Windows NT\CurrentVersion\ProfileList\$($sid)" -Name ProfileImagePath).replace("$(gpv 'HKLM:\Software\Microsoft\Windows NT\CurrentVersion\ProfileList' -Name ProfilesDirectory)\",'')}catch{$Sid}

        #' Various info
        ((gi $infoFile -force).length / 1mb).ToString('0.00MB')
        ((gi $originalFile -force).length / 1mb).ToString('0.00MB')

        # Blow it all Away
        #ri $InfoFile -Recurse -Force -Confirm:$false -WhatIf
        #ri $OriginalFile -Recurse -Force -Confirm:$false- WhatIf
        # remove comment before two lines above and the '-WhatIf' statement to delete files

# Refresh desktop icons


ie4uinit.exe -ClearIconCache

end scripting enjoy.
  • 1
    This look nice, but why all the drive stuff in there? – not2qubit Jan 9 '20 at 20:33

The line from the accepted answer worked for me very sporadically. I ended up writing a while loop to call the code silently in the background 25 times. Hope this helps.

Code from the accepted answer:

RUNDLL32.EXE USER32.DLL,UpdatePerUserSystemParameters 1, True

Code from the top of my bash script:

desktop () {


# Tell the desktop to refresh 25 times.
while [ $i -le 25 ]
  echo "RUNDLL32.EXE USER32.DLL,UpdatePerUserSystemParameters, 1 True"| "C:/Windows/System32/WindowsPowerShell/v1.0/powershell"


# This runs the function silently as a background process
desktop &>/dev/null &

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