Installshield Product Code May 2026

| Identifier | Purpose | When to Change | | :--- | :--- | :--- | | | Identifies a specific version of an application. | For major upgrades and patches. | | Upgrade Code | Links all versions of the same product family. | Never change this. Remains constant across all versions. | | Package Code (MSI only) | Identifies the unique .MSI file itself. | Changes every time you build. |

Many developers treat the Product Code as just another GUID (Globally Unique Identifier) generated by a wizard. However, getting it wrong can lead to "side-by-side" installation disasters, orphaned registry entries, or the dreaded error: "Another version of this product is already installed." installshield product code

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\ProductCode For 64-bit applications on 64-bit Windows, check: | Identifier | Purpose | When to Change

You must not change the Product Code for a patch targeting an existing version. The patch is designed to update a product in place. | Never change this