This is a follow-up. The previous scripts had compatibility issues with older Win 95+ OS's-based Screensavers etc. (they wouldn't detect the Wallpaper like in the BLOCKS/ Windows 98.SCR screensaver)
Legacy Windows 98 Screensaver Compatibility Fix via PowerShell
The issue stems from two primary compatibility gaps between modern Windows 10 and legacy Win32/16 architecture:
- Image Format Limitation: Legacy screensavers (e.g., Windows 98.SCR) lack JPEG/PNG decoding capabilities and rely solely on uncompressed BMP files for textures.
- Registry Synchronization: Modern Windows 10 manages wallpaper transcoding internally, often failing to update legacy registry keys (HKCU:\Control Panel\Desktop\Wallpaper) with raw image paths, causing detection failures.
Solution Overview:- On-the-fly BMP Conversion: The script leverages .NET's System.Drawing to transcode any user-selected image (JPG, PNG, WebP) into a 24-bit BMP, ensuring compatibility.
- Reliable Storage Path: Saves the BMP to a predictable, short path (e.g., $env:USERPROFILE\classic_wallpaper.bmp) to facilitate detection by legacy screensavers.
- Registry & API Updates: Manually updates the Wallpaper registry key with the BMP path and invokes SystemParametersInfo API with SPI_SETDESKWALLPAPER to immediately apply, ensuring the screensaver detects the correct wallpaper image.
You need five of these scripts for each of the modes (replace the code lines of each according to the following):
+--------------------------------------------------------+
| Style Reference Map |
+------------------------------+-------------------------+
| Style | Registry Settings |
+------------------------------+-------------------------+
| Stretch | WallpaperStyle='2' |
| | TileWallpaper='0' |
+------------------------------+-------------------------+
| Fit | WallpaperStyle='6' |
| | TileWallpaper='0' |
+------------------------------+-------------------------+
| Fill | WallpaperStyle='10' |
| | TileWallpaper='0' |
+------------------------------+-------------------------+
| Center | WallpaperStyle='0' |
| | TileWallpaper='0' |
+------------------------------+-------------------------+
| Tile | WallpaperStyle='0' |
| | TileWallpaper='1' |
+------------------------------+-------------------------+
| Span | WallpaperStyle='22' |
| | TileWallpaper='0' |
+------------------------------+-------------------------+
1. Here's the full script for 'Stretched', change the two values and repeat for the rest of the scripts modes (Gemini 3.5 Flash AI Generated):```SetWallpaperMCStretch.ps1
param([string]$ImagePath)
# Validate file exists
if (-not (Test-Path $ImagePath)) {
Write-Error "File not found: $ImagePath"
exit 1
}
# Load .NET Assembly for Image Processing
Add-Type -AssemblyName System.Drawing
# Define a clean, static path for the legacy BMP file
# Legacy screensavers handle paths without spaces much better
$BmpPath = "$env:USERPROFILE\classic_wallpaper.bmp"
# Convert the source image to a 24-bit BMP to satisfy the Win98 screensaver engine
try {
$SrcImage = [System.Drawing.Image]::FromFile($ImagePath)
# If a previous wallpaper BMP exists, delete it first to release file locks
if (Test-Path $BmpPath) {
Remove-Item $BmpPath -Force -ErrorAction SilentlyContinue
}
# Save as BMP format
$SrcImage.Save($BmpPath, [System.Drawing.Imaging.ImageFormat]::Bmp)
$SrcImage.Dispose()
}
catch {
Write-Error "Failed to process and convert image: $_"
exit 1
}
# Set style: Stretch (Style '2', Tile '0')
Set-ItemProperty -Path 'HKCU:\Control Panel\Desktop' -Name WallpaperStyle -Value '2'
Set-ItemProperty -Path 'HKCU:\Control Panel\Desktop' -Name TileWallpaper -Value '0'
# FORCE legacy wallpaper path update in the registry for the screensaver
Set-ItemProperty -Path 'HKCU:\Control Panel\Desktop' -Name Wallpaper -Value $BmpPath
# Apply wallpaper via Win32 API
Add-Type -TypeDefinition @"
using System;
using System.Runtime.InteropServices;
public class Wallpaper {
[DllImport("user32.dll", CharSet = CharSet.Auto)]
public static extern int SystemParametersInfo(int uAction, int uParam, string lpvParam, int fuWinIni);
}
"@ -ErrorAction SilentlyContinue
# SPI_SETDESKWALLPAPER = 0x0014 (20)
# SPIF_UPDATEINIFILE | SPIF_SENDCHANGE = 3
[Wallpaper]::SystemParametersInfo(20, 0, $BmpPath, 3)
```
2. Plus interface it in MC 'User-Defined Command' script like this (replace the FilePath in the script with your local path (ensure directory separators are escaped with double backslashes \\).):```MultiScript
@var $imgPath = GetSourceFocusPath();
@var $arguments = "-ExecutionPolicy Bypass -File \"C:\\Path\\To\\SetWallpaperMCStretch.ps1\" -ImagePath \"" + $imgPath + "\"";
MC.Run CMD="cmd.exe /c powershell.exe" ARG="{$arguments}";
```
Notes:
Tested on MC 16.0 running on Windows 10.
To add to the context menu: navigate to Config > "Custom Context Menu" and add the script.
Technical Highlights:- Uses PowerShell + .NET for image transcoding.
- Sets appropriate registry values (WallpaperStyle and TileWallpaper) for correct display behavior.
- Invokes Win32 API call for immediate wallpaper refresh.
- Ensures backward compatibility for Win95/98-style screensavers expecting BMP textures and registry cues.
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