Updating WIX transformations - wix

Question

I'm trying to create an installer (using WIX 3.11) which can install more instance's of the same program. I have managed to create an installer which does that, but the installer does not work when trying to do an update of the different instances
Here's my code
<?xml version="1.0" encoding="UTF-8"?>
<Wix xmlns="http://schemas.microsoft.com/wix/2006/wi">
<Product Name="ABC Default" Manufacturer="Inc" Language="1033" Version="1.0.1.7"
Id="*"
UpgradeCode="{3984A5B2-5CDA-4EC8-933A-089E46E2D688}">
<Package Id="*" InstallerVersion="200" Compressed="yes" InstallScope="perMachine"
Keywords="Installer" Description="Installer"
Comments="Instance installer" Manufacturer="Me"
Platform="x64"/>
<Property Id="WIXUI_INSTALLDIR" Value="INSTALLFOLDER" />
<UI>
<UIRef Id="WixUI_InstallDir" />
<!--Skip license dialog-->
<Publish Dialog="WelcomeDlg"
Control="Next"
Event="NewDialog"
Value="InstallDirDlg"
Order="2">1</Publish>
<Publish Dialog="InstallDirDlg"
Control="Back"
Event="NewDialog"
Value="WelcomeDlg"
Order="2">1</Publish>
</UI>
<MajorUpgrade AllowSameVersionUpgrades="yes" Schedule="afterInstallInitialize" DowngradeErrorMessage="A later version of [ProductName] is already installed" />
<MediaTemplate />
<Property Id="INSTANCEID" Value="0" />
<InstanceTransforms Property="INSTANCEID" >
<Instance Id="DEV" ProductCode="*" UpgradeCode="{BB75B4BE-6217-4FDA-8BAC-C46B402AC0FB}" ProductName="ABC Dev" />
<Instance Id="TEST" ProductCode="*" UpgradeCode="{ACFEFC2F-0D48-4640-9BBC-6E1162F9D1E7}" ProductName="ABC Test" />
</InstanceTransforms>
<Feature Id="ProductFeature" Title="Products" Level="1">
<ComponentGroupRef Id="ProductComponents" />
</Feature>
<CustomAction Id="SetInstanceDirectory"
Property="InstanceDirectory"
Value="[INSTALLFOLDER][INSTANCEID]\"/>
<InstallExecuteSequence>
<Custom Action="SetInstanceDirectory"
Before="CostFinalize"><![CDATA[InstanceDirectory = ""]]></Custom>
</InstallExecuteSequence>
</Product>
<Fragment>
<Directory Id="TARGETDIR" Name="SourceDir">
<Directory Id="ProgramFilesFolder">
<Directory Id="INSTALLFOLDER" Name="Inc" >
<Directory Id ="InstanceDirectory" Name="Instance"/>
</Directory>
</Directory>
</Directory>
</Fragment>
<Fragment>
<ComponentGroup Id="ProductComponents" Directory="InstanceDirectory">
<Component Id="NotepadComponent" Guid="{52BCDD67-47F3-4F04-A7F9-6CAB42010CDE}" MultiInstance="yes">
<File Source="c:\Windows\System32\notepad.exe"/>
</Component>
</ComponentGroup>
</Fragment>
</Wix>
As can be seen the installer is quite simple, but I need some help on the updating part.
Install procedure:
msiexec /i test_installer.msi
msiexec /i test_installer.msi MSINEWINSTANCE=1 TRANSFORMS=":DEV"
/l*vx log.log
msiexec /i test_installer.msi MSINEWINSTANCE=1 TRANSFORMS=":TEST"
/l*vx log.log
Update procedure:
msiexec /i test_installer.msi
msiexec /i test_installer.msi TRANSFORMS=":DEV" /l*vx log.log
When trying to update the DEV instance, the installer tries to update the default installation informing the user that the installation is up-to-date and repair or uninstall are possible.
Please help. I have been looking at this problem for more than a week now.
/Kenneth

Answer 1

MSINEWINSTANCE=1 should be specified always, because your updates are provided as major upgrade.
I just had a look at some code that uses instance transforms. There is no distinction between first install and upgrade install, the command-line is always the same.
This makes sense as a major upgrade is like a new product installation, the only difference being that it automatically removes the older version.