How to preserve Windows Service credentials during major upgrade in WiX 3.14 (without reinstalling the service)

[sharma021]

I have an MSI built with WiX 3.14 that installs a Windows Service using and .
By default, the service runs under LocalSystem.

After installation, users often manually update the Log On account (username + password) in Services.msc.
During a major upgrade, I need to preserve these credentials — i.e., prevent the service from being removed or recreated — while still updating the EXE.

What happens now
• On upgrade, the old service is removed and recreated.
• This resets it back to LocalSystem and wipes out the manually entered credentials.
• The new EXE installs fine, but credentials are lost.

Goal

During major upgrades:
• Keep existing service registration intact.
• Preserve user-entered credentials.
• Replace only the EXE and restart the service.

Questions
• How can I stop WiX/MSI from uninstalling/reinstalling the service during a major upgrade?
• Is skipping InstallServices (when the service exists) considered safe?
• If the EXE path changes, what’s the correct way to update only the service ImagePath without touching credentials?
• Any known clean patterns or sample WiX snippets for this?

Environment:
WiX 3.14 | Windows 10/11

Thanks in advance for any insights or working examples! 🙏

[robmen]

Not an answer, but just so you know, WiX v3 is very much out of service and no longer receives security updates. I highly recommend upgrading to a supported version of WiX (v5 for a few more months or v6 for longer).

[sharma021]

Thanks for the clarification!

I understand WiX 3.x is no longer maintained. Unfortunately, this MSI is part of a legacy enterprise product that’s locked to WiX 3.14 for the time being (corporate build environment and QA baselines).

Given that upgrade is not immediately possible, could you please suggest even conceptually how this scenario should be handled in WiX v4/v5/v6?

If the same logic (skipping InstallServices or preserving service configuration)exists in newer versions, I can try backporting a similar approach manually in 3.14.

Specifically, I’m trying to:
• Prevent from resetting credentials during major upgrade.
• Replace the service executable only.
• Ensure uninstall still cleans up properly if user removes the product completely.

Any hints on the correct pattern in v4/v5 that achieves this would really help me reason about what to replicate in 3.14.