How do I make a WIX MSI always remove a previous version?

Question

I have CI build system builds an MSI whenever a developer checks in a change. We run automated acceptance tests on the installed MSI.

Basically every MSI is a comple

Answer 1

You can use this code to remove the old version and install a newer one:

<Product Id="*"
         UpgradeCode="87795f3dc95-81f5-473e-955e-2871a5bd66a5"
         Name="AppName"
         Language="1033"
         Version="1.0.6"
         Manufacturer="Manufacturer Name">
  <Package InstallerVersion="200" Compressed="yes" InstallScope="perMachine" />
  <MajorUpgrade Schedule="afterInstallInitialize"
                DowngradeErrorMessage="A later version of [ProductName] is already installed"
                AllowSameVersionUpgrades="yes" />
</Product>

Answer 2

If the product code and version are the same yet the package code is different, you will always get that Windows Installer error message.

I would strongly suggest including version information for your installers in your CI builds. If you are installing and subsequently upgrading each build, then versioning isn't a bad thing to have. It should be relatively easy to add this to a CI build.

Answer 3

So I did find a way of doing it without changing the version number.

I change the Product GUID with every build, but keep the Upgrade GUID the same.

I also had to change the RemoveExistingProducts to Before='InstallInitialize'. Otherwise it left only the 'deltas' between builds in the install path.

As noted by Wim below, I can replace the generated Product GUID with '*'.

Answer 4

try

<InstallExecuteSequence>
  <RemoveExistingProducts After='InstallFinalize' />
</InstallExecuteSequence>

This should remove any existing products after the install is finalised though you could customize the point at which you do it

see http://mohundro.com/blog/2009/02/23/getting-started-with-wix-and-major-upgrades/

also see the accepted answer for this question