When you try to install or uninstall a program in Windows, an error may occur:
Error 1618: Another installation is already in progress. Complete the installation before proceeding with the install.
Error 1500: Another installation is in progress. You must complete that installation before continuing this one.
However, no other visible installation programs are running. Even a computer restart doesn’t solve the problem.
This issue indicates that a Windows Installer background process is running on the computer that started the software installation from an MSI package. Windows Installer can only run one active install/uninstall transaction at a time. To install a new program from an MSI package, first end the process that is currently running.
To find out which application is installed in the background by the MSI installer, open Task Manager and add the Command line column to the process Details tab.
Now all processes are listed with the commands they were started with. Find all of the msiexec.exe processes and see which of the MSI packages are currently being installed.
You can also use PowerShell to list all the MSI packages that are currently running:
Get-CimInstance Win32_Process -Filter "name = 'msiexec.exe'" | Select-Object Name, ProcessId, CommandLine
To continue installing a new application, you must first complete the installation of any programs that are already running.
You can stop a specific msiexec installation process by its PID:
taskkill /pid 6256 /F
Or kill all Windows Installer background processes at once:
taskkill /IM msiexec.exe /FOnce this is done, you can re-run the MSI/EXE to install the required software.