Using MSI Transforms (MST) with Patch My PC

Problem

Some organizations need to deploy TechSmith (or other MSI‑based) applications with a custom MST file. Patch My PC supports MSTs but does not import, store, or embed them directly. This article explains how Patch My PC handles MST files, how to configure them correctly, and where to store them so they continue to work during updates.

Solution

Patch My PC supports MST files by passing them through the MSI command line using the standard TRANSFORMS= parameter. The MST must be stored in a location accessible to the SYSTEM account, and referenced in the application’s Install Command Line within the Patch My PC Publishing Service.

How Patch My PC Uses MSI + MST

Patch My PC installs applications using the vendor MSI and applies your MST at install time by injecting parameters into the MSI command.

Example MSI syntax:

msiexec /i app.msi TRANSFORMS=Yourtransform.mst

Patch My PC reuses this same command line during every update, ensuring customizations persist.

Configure MSTs in Patch My PC

1. Open the Patch My PC Publishing Service.
2. Select Applications.
3. Choose the application (for example, Snagit, 7‑Zip, Java).
4. Select Deployment Options.
5. In Install Command Line, add the MST parameter:

TRANSFORMS=YourTransform.mst

Patch My PC will:

• Download the vendor MSI
• Apply the MST at install time
• Install silently
• Reapply the MST during updates

Where to Store the MST File

Option 1 (Recommended): Store MST with the App’s Content Source

Place the MST in the same directory as the MSI:

\\Server\Share\PatchMyPC\AppName\
├ AppName.msi
├ AppName.mst

Then reference only the file name:

TRANSFORMS=AppName.mst

Note: The SYSTEM account must be able to read this location.

Option 2: Use a Full UNC Path

TRANSFORMS=\\Server\Share\Transforms\AppName.mst

Warning: Using UNC paths is less reliable. If the SYSTEM account cannot access the path, the transformation will fail.

Behavior During Updates

When Patch My PC publishes a new version of the application:

• The MST parameter is reused
• The MST is applied again automatically
• All MST customizations persist

This applies to all MSI‑based applications, our EXE files will not work with an MST.

• MST files cannot be used with EXE installers
• Use vendor‑provided silent switches instead
• Patch My PC handles many EXE installers automatically

Common Issues

MST Not Applying

Cause: MST not stored in a SYSTEM‑accessible location.

Fix: Store MST in the same directory as the MSI or a reliable UNC path.

Customizations Not Sticking After Updates

Cause: Patch My PC cannot find the MST during the update.

 Fix: Keep MST files stored permanently in the content source.

Incorrect Syntax

Cause: Typographical errors in the Install Command Line.

 Fix: Test syntax manually:

msiexec /i Snagit.msi /qn /norestart TRANSFORMS=Snagit.mst

Important Notes

• Do not store MST files in a user profile
• Do not use local paths
• Ensure SYSTEM can read the directory
• Disable Snagit auto‑updates so Patch My PC manages updates

Best Practices

• Use MSTs only with MSI installers
• Store MSTs in the same directory as the MSI
• Use consistent naming for MST files
• Test installs manually before adding them to Patch My PC
• Keep MST files available permanently to ensure update compatibility

Disclaimer: We’re not Patch My PC experts, but we did our research. This article is based on hands-on testing and reputable technical sources to surface the best solutions we could find. Tech changes fast, so if something is inaccurate or outdated, please reach out and let us know.