How to retain file association of previous version after removing new version in WiX?

Question

I have Product A with Versions 1.0.0 and V2.0.0 each associated with file type xyz (to executable product.exe) using WiX File association. When Product A V1.0.0 is installed, then file extension xyz is associated. Next, I install Product A V2.0.0, now the file xyz is associated with Product A V2.0.0. File association is overridden as expected or vice-versa if 2.0.0 is installed first and later V1.0.0.

If I uninstall V2.0.0 then the file association is removed for 2.0.0 and association of V1.0.0 is not restored and vice-versa.

How do I get the the file association restored for previous version automatically using WiX? Please see my WiX code below and suggest any possible corrections.

Product A V1.0.0 WiX 3.8 code:

<?xml version="1.0" encoding="UTF-8"?>
<Wix xmlns="http://schemas.microsoft.com/wix/2006/wi">
    <Product Id="PUT-GUID-HERE" Name="Product A 1.0" Language="1033" Version="1.0.0.0" Manufacturer="Microsoft" UpgradeCode="PUT-GUID-HERE">
        <Package InstallerVersion="200" Compressed="yes" InstallScope="perMachine" />

        <MajorUpgrade DowngradeErrorMessage="A newer version of [ProductName] is already installed." />
        <MediaTemplate />

        <Feature Id="ProductFeature" Title="Product A 1.0" Level="1">
            <ComponentGroupRef Id="ProductComponents" />
        </Feature>
    </Product>

    <Fragment>
        <Directory Id="TARGETDIR" Name="SourceDir">
            <Directory Id="ProgramFilesFolder">
                <Directory Id="INSTALLFOLDER" Name="Product A 1.0" />
            </Directory>
        </Directory>
    </Fragment>

    <Fragment>
      <ComponentGroup Id="ProductComponents" Directory="INSTALLFOLDER">
      <!-- TODO: Remove the comments around this Component element and the ComponentRef below in order to add resources to this installer. -->
        <Component Id="ProductComponent" Guid="PUT-GUID-HERE">
          <File Id="openBox" Source="D:\open-box.ico" />
          <File Id="wpfFile" Source="D:\product.exe" />
          <ProgId Advertise="no" Description="My WPF File" Icon="openBox" Id="xyzFileAssociation_1_0">
            <Extension Id="xyz" ContentType="application/xyz">
              <Verb Id="open" Command="open with my app" Argument="&quot;%1&quot; &quot;1.0.0&quot;" TargetFile="wpfFile"/>
            </Extension>
          </ProgId>
        </Component> 
      </ComponentGroup>
    </Fragment>
</Wix>

Product A V2.0.0 WiX 3.8 code:

<?xml version="1.0" encoding="UTF-8"?>
<Wix xmlns="http://schemas.microsoft.com/wix/2006/wi">
    <Product Id="PUT-GUID-HERE" Name="Product A 2.0" Language="1033" Version="2.0.0.0" Manufacturer="Microsoft" UpgradeCode="PUT-GUID-HERE">
        <Package InstallerVersion="200" Compressed="yes" InstallScope="perMachine" />

        <MajorUpgrade DowngradeErrorMessage="A newer version of [ProductName] is already installed." />
        <MediaTemplate />

        <Feature Id="ProductFeature" Title="Product A 2.0" Level="1">
            <ComponentGroupRef Id="ProductComponents" />
        </Feature>
    </Product>

    <Fragment>
        <Directory Id="TARGETDIR" Name="SourceDir">
            <Directory Id="ProgramFilesFolder">
                <Directory Id="INSTALLFOLDER" Name="Product A 2.0" />
            </Directory>
        </Directory>
    </Fragment>

    <Fragment>
        <ComponentGroup Id="ProductComponents" Directory="INSTALLFOLDER">
            <!-- TODO: Remove the comments around this Component element and the ComponentRef below in order to add resources to this installer. -->
             <Component Id="ProductComponent" Guid="PUT-GUID-HERE">
               <File Id="openBox" Source="D:\open-box.ico" />
               <File Id="wpfFile" Source="D:\product.exe" />
               <ProgId Advertise="no" Description="My WPF File" Icon="openBox" Id="xyzFileAssociation_2_0">
                 <Extension Id="xyz" ContentType="application/xyz">
                   <Verb Id="open" Command="open with my app" Argument="&quot;%1&quot; &quot;2.0.0&quot;" TargetFile="wpfFile"/>
                 </Extension>
               </ProgId>
             </Component> 
        </ComponentGroup>
    </Fragment>
</Wix>

Only difference is in the ProgId's Id w.r.t file association.

Answer 1

Change the file association(s) to include a version number as part of its caption: xyz1, xyz2, etc... Only do this if you want the products to be possible to install side-by-side. This avoids interference between your products. The alternative would be to register your file associations via a custom action run on uninstall that would look for your other installations. Very clunky and error prone if you ask me. Rule of thumb in my world: Always chose to rely on small changes in application and setup design to avoid custom solutions with added risk. If you can reliably avoid read/write custom actions that is always the right call for reliability and simplicity.

I prefer to avoid side-by-side installations since it is rare that two versions of a software are actively maintained. The exception might be major versions released to the public - in other words version 1, 2, 3 etc... I wouldn't mess with new associations per build to put it like that.

If you want to install side-by-side you must change all component guids for components that are installed side-by-side, and use proper merge modules or wix includes for shared files that aren't installed side-by-side (typically COM servers and the like that can only be installed once per-machine). This is in order for reference counting to work correctly. Perhaps this answer is worth a quick read: Change my component GUID in wix?. Or better yet, rely on automatic, generated guids as described in the linked post.

Perhaps also have a look at this:

• MSI Reference Counting: Two products install the same MSIs
• How to include wxi file into wxs?