QuickBooks Error 1618: Fixing "Another Installation in Progress"

Last reviewed 2026-07-03 4 min read

Resolve QuickBooks Desktop Error 1618, part of the Windows 1xxx installer family. Learn what causes this "installation in progress" bug and how to fix it o

When you are trying to install, update, or repair QuickBooks Desktop and get stopped by Error 1618, it means Windows thinks another installation is already running. This is part of the 1xxx Windows-installer family of errors. If you are maintaining an older, discontinued version of QuickBooks Desktop, this roadblock can be particularly frustrating—but it is entirely fixable on your own machine without needing Intuit's support or an upgrade.

What Error 1618 Means in Plain English

Error 1618 is a Windows Installer error code, not a QuickBooks-specific bug. Whenever Windows Installer (msiexec.exe) is actively processing a package, it places a lock on the installation queue. If QuickBooks (or its background services) attempts to launch a second installation routine while the first is still finishing up, Windows blocks it and throws Error 1618.

Common Causes

This error almost always boils down to a timing or process conflict. The usual culprits include:

Legitimate background installations: Windows Update or a Microsoft Office update might be running silently in the background, tying up the installer.
Stuck processes: A previous QuickBooks update or installation failed to close out properly, leaving a ghost process running in the background.
Multiple QuickBooks triggers: You might have clicked the installer or update prompt more than once out of impatience, triggering parallel installation attempts.

The 1xxx Windows-Installer Family

Error 1618 belongs to the broader 1xxx family of Windows Installer errors (which includes nearby codes like 1603, 1622, or 1601). If you are seeing this error, any troubleshooting steps aimed at the 1xxx family will generally apply. These errors all relate to the environment in which the software is being installed—meaning the issue is with Windows, not your QuickBooks company file.

How to Fix Error 1618 Yourself

You can resolve this by clearing the installation queue and repairing the QuickBooks installation environment. Follow these steps in order:

Stop Conflicting Installations: Save your work and restart your computer. A simple reboot clears out stuck msiexec.exe processes and flushes the Windows Update queue. Do not open QuickBooks immediately after rebooting.
Run the QuickBooks Install Diagnostic Tool: Open the QuickBooks Tool Hub (if you don't have it, you can download the Tool Hub installer from an archived source or transfer it via USB). Go to the Installation Issues tab and select QuickBooks Install Diagnostic Tool. Let it run—this can take up to 20 minutes. It will automatically detect and fix corrupted Microsoft components and registry keys that cause 1xxx errors.
Perform a Clean Install: If the diagnostic tool doesn't clear the error, you may need to uninstall QuickBooks Desktop, rename the old installation folders left behind in C:\Program Files\Intuit and C:\ProgramData\Intuit, and then reinstall QuickBooks from your saved installer file.

Why Archived Installers Keep You Protected

If you are running a discontinued version of QuickBooks Desktop, having a local, archived copy of your specific installer file (the .exe or .msi file) is your best defense against Error 1618.

When Intuit sunsets a version, they eventually remove the installation files and digital reactivation servers from their active network. If Error 1618 forces you to perform a clean uninstall and reinstall, users relying on Intuit's servers for a fresh download will be out of luck. Because you have the installer saved locally, you can bypass Intuit's network entirely, run the installation offline, and get your software back up and running independently.

Preventing the Error from Recurring

To keep Error 1618 from popping back up, always check for pending Windows Updates before modifying your QuickBooks installation. If you are applying a manual patch or update to an older Desktop version, close all other programs, temporarily pause your antivirus, and ensure you only click the installer once. Give the process plenty of time to finish before opening QuickBooks.

When to Check Your Company File

Because Error 1618 is strictly a Windows installation conflict, it will not damage your company file (.qbw). However, if you experienced a sudden power loss or a hard crash while the error was occurring, your company file might have been left in a vulnerable state. If QuickBooks finally opens but your data seems incomplete, or you receive separate data-damage warnings, you should run the QuickBooks File Doctor to verify the integrity of your company file and rebuild damaged data tables.