All morning long I’ve been battling my Windows 7 system. I finally found out that the error code which reads:
“Error 1500. Another installation is in progress. You must complete that installation before continuing this one.”
can be attributed to the InProgress key found in the registry at
After doing a little searching on the web, I found that Microsoft has a program called msizap.exe which can be found in the Windows Installer SDK. The problem with that is that the SDK itself is an .msi file. I didn’t really want to install the full SDK anyway. So I searched some more and came across the Windows Installer Cleanup Utility. This was mainly created to clean-up an Office installation gone bad. Again, an .msi file. So, I went back to the Windows Installer SDK and downloaded it. To trick the system into letting me install it, I simply deleted the key mentioned above (HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Installer\InProgress). At first attempt, I received an error. I tried deleting it again and it worked. Went through the installation process only to receive the same error. After I refreshed the registry, I saw that it was back. It pointed to a .ipi file contained in the C:\Windows\Installer directory. At this point, I still don’t know what this installer is that is still hung up. I opened several of these files from today and the reference Visual Studio 9.0. I’ll see if I can track down what is later.
Anyway, I finally decided to quick hit delete on the key and then quickly hit retry on the installation. It worked. My installation continued. At the very end a refresh of the registry showed that the other application came back and added an InProgress key again.
It appears to only delete the key in the registry just like the above. I saw that in my case, the InProgress key still comes back. I guess it’s purpose is so that you don’t touch the registry.
I’ll add an update to this post if I find out how to completely kill that other installation package.