I install a ton of pre-release and test software so it is not surprising that I sometimes run into Windows Installer issues. Here is an entertaining error though. It is unlikely, I guess, that you will hit this problem; but I present it as an illustration of what can go wrong, as we move into the era of locked-down operating systems and easy app installs. Though even these are not perfect. Notice how the operating system fights me all the way.

Years ago I installed Microsoft’s Office Labs Ribbon Hero, a tutorial add-on for Office. At the time I was running Windows Vista. Since then I have done an in-place upgrade to Windows 7. I tried to remove it today through Control Panel and got this message:

After presenting this information setup closed and the application was not uninstalled.

So … the application does not support Windows 7 and therefore you cannot remove it. Clever, and I found this a tricky problem to get around.

I took a look at the Windows installer files which you can find in %SYSTEMROOT%\Installer. All the msi files have random names. However, you can right-click the column heading area and choose More, then check Subject in the list. Click OK, and now the application to which each msi relates appears.

Now you can click the column heading to sort by subject and find the problem msi.

I copied the msi to my desktop.

For the next step you need the Orca tool from the Windows Installer SDK. If Orca is installed, you can right-click the MSI and choose Edit with Orca.

I then selected LaunchCondition and deleted the launch condition that required Windows XP.

INSTALLED OR VersionNT = 501 OR APPLYING_AUTOUPDATE

Hmm, something odd here as it should pass INSTALLED? Still, save, right-click the msi, choose Uninstall. You still hit the error. Why? Somehow, Windows works out that you are uninstalling a product for which an msi exists in the official location and uses that one instead. You have to copy your modified msi to the correct location. Open an administrator command prompt:

Now right-click the msi and choose Uninstall.

It worked. Phew.