I'm working on an MSI installer with WiX. I'm trying to keep this as simple to develop as possible: this is an internal product, and my users are our IT personnel.

The product includes a Windows Service that must be configured to run under a different account for each machine.

The workflow I was planning for my users (for first-time install) is as follows:

1. Run the installer
(The installer sets up the service under a default account)
2. Stop the service via `sc` or Local Services applet
3. Update the service properties to run under the correct machine-specific account.
(The account is different for each machine, and only the IT personnel has access to the passwords.)
4. Restart the service

Subsequent updates would consist of installing from updated MSI files.

Testing a "small" update, I was surprised to find that the installer reset the service back to running under the default account. This is a major problem for me because it makes it really hard for my users to update their servers. They would have to re-enter the account information on each machine every time there is an update. I expected that would happen with a "major" update, but not on a "small" one.

1. **Is there a way to configure the installer so that it does not change the existing account/password configuration for a service during a "small" or a "minor" update?**
2. Will this happen during a "repair" as well (I haven't tried that)?

Here's what my component looks like in the `.wxs` file:

```
<Component Id="cmpService" Guid="{MYGUIDHERE}">
  <File Id="filService" KeyPath="yes" Name="ServiceApp.exe" />
  <ServiceInstall Id="ServiceInstall" Name="ServiceApp" DisplayName="My Service"
                  Type="ownProcess" Start="auto" ErrorControl="normal"
                  Account="LocalSystem">
    <util:PermissionEx ... attributes here... />
  </ServiceInstall>
  <ServiceControl Id="StartService" Start="install" Stop="both" Remove="uninstall"
                  Name="ServiceApp" Wait="yes" />
</Component>

```

I had expected that `Remove="uninstall"` would preserve the service in place if there were no changes to it. Apparently not. (I'm not too worried if this happens on "major" updates).

I also noticed that the `ServiceConfig` element has attributes (`OnReinstall`) that seem to fit the bill, but based on candle error messages, it's pretty clear that `OnReinstall` is intended to affect only the configuration members of the element (`PreShutdownDelay`, etc.) rather than the service installation as a whole.

I've looked into these:

* [Let the user specify in which account a service runs](https://stackoverflow.com/q/9568169)
* [WiX MajorUpgrade of Windows Service, preserving .config, and avoiding a reboot](https://stackoverflow.com/q/23349685)
* [How to only stop and not uninstall windows services when major upgrade in wix?](https://stackoverflow.com/q/15965539)

Curiously, [this answer](https://stackoverflow.com/a/23547743) suggests that this is an issue only for "major" upgrades. That wasn't my experience. Was my experience a fluke?

* [How do I create a custom dialog in WiX for user input?](https://stackoverflow.com/q/787811)

It would have been OK prompting for an account and password during installation, but storing the password in the registry or elsewhere is a not really an option in this case, and having to reenter the credentials on every update is just as disruptive as having to reconfigure the service by hand.