Fix for Windows Error 1500: Another installation is in progress. You must complete that installation before continuing this one.

Open Services and find Windows Installer.

Change Startup from Manual to Disabled.

Open [Task Manager >> Processes]

Check “Show processes from all uses”

Find the process (might occur more than once, usually msiexec.exe or msiexec32.exe), right click and select “End Process”.

Click Yes for Warning prompt.

Open RegEdit.

Delete the Key: HKEY_Local_MachineSoftwareMicrosoftWindowsInstallerInProgress

Now open Windows Services by typing services.msc in Start>Run

Find out the service named Windows Installer from the list of available services. Change back to Manual.

That’s it. Try to install the failed software. You’ll succeed.