An installation fails to start with the following error:
Error 1500: Another installation is in progress. You must complete the installation before continuing this one.
Download the Diagnostic
There are certain situations when missing entries in your registry and registry corruption causes this problem. Try running a registry scan to identify if there are any such issues.
- Click the button below to download and install the Diagnostic
- Perform a Registry scan and fix any problems detected.
- Restart your computer.

Estimated Download Time: 10 Seconds
Quit Another Installation
As the error clearly indicates, an installation is already running on your system. Abort the installation and then try again.
Quit Background Process
Figure out and forcefully abort the background installer process using the Task Manager.
1. Press Windows Key + X; choose Task Manager.
2. Click “More Details” to expand the user interface.
3. End the following tasks from Processes tab:
- Msi.exe
- Setup.exe
- Installer.exe
If no such items are found on the Processes tab, look at the Details tab. Click an item, and then “End task” button.
Stop Windows Installer Service
Use the Services tool to terminate Windows Installer service.
1. Type “services.msc” in the Search Box on your Taskbar.
2. Scroll down; right click “Windows Installer” service, and choose Stop option.
Restart the PC
Restart the computer and try loading the installer again.
Remove Installation References
A previous installation hasn’t removed Registry reference containing information about active installation status. Delete the Registry reference and then reinitiate the setup.
1. Type “RegEdit” in Search Box and open that.
2. Locate the following subkey:
- HKEY_LOCAL_MACHINE | SOFTWARE | Microsoft | Windows | CurrentVersion | Installer | InProgress
3. Double click “Default” string; delete its value.
4. Click OK, and then exit.
Reregister MSIEXEC
MsiExec file entries need to be repaired. Unregister and reregister the Registry entries about Windows Installer components.
1. Open elevated Command Prompt. Press Windows Key + X; choose Command Prompt (Admin).
2. Execute below commands:
- Msiexec /unreg
- Msiexec /regserver
- exit
3. Restart the computer.
Use Clean Boot
Place your computer in clean boot mode. It starts Windows with a minimal set of startup items and drivers.
1. Type “MsConfig” in Search Box, press ENTER.
2. Choose “Selective startup” option from General tab.
3. Uncheck the box named “Load startup items,” and then save the changes by clicking Apply, and then OK.
Reinstall Windows Installer
Delete Windows Installer component files and reinstall the package.
1. Double click This PC icon on Desktop.
2. Open the following location:
- C:\Windows\System32\
3. Delete the following files:
- Msi.dll
- Msiexec.dll
- Msihnd.dll
4. Download latest Windows Installer version from Microsoft Download Center. Use the Search feature.