While installing or updating QuickBooks, users may encounter an error
message that says, "Windows Installer is not accessible." This
message appears with a specific error code, 1601, and interrupts the
installation or updates.
Many reasons can trigger this error on your system, such as a problem
with the installer file, outdated Windows, and misconfigured security
settings. The segment below will discuss all the troubleshooting steps
you need to take to fix this issue. Let’s explore.
 The “Windows Installer is not accessible” error message indicates the
appearance of error 1601. You may get this error message for the following
reasons.
 Misconfigured security settings can block the update installation in QuickBooks,
leading to error 1601 and QuickBooks error 1603.
 Incomplete program installation can trigger this error.
 When the installer file itself is corrupted, you will see this error.
 Recommended to Read:- How Do I Fix QuickBooks Update Error 15311?
 Open the Windows Start menu.
 Search for Control Panel.
 Launch Control Panel.
 Go to Programs and Features/Uninstall a Program.
 To remove QuickBooks Desktop, locate and select and select it from the list of programs.
 Click Uninstall/Change, then Remove, and follow with Next.
 If you don’t see these options, try signing out and back into Windows as an admin or a user
with admin rights.
 Step 2: Reinstall QuickBooks Desktop:
 After removing QuickBooks, proceed to install QuickBooks Desktop again.
 During installation, QuickBooks will automatically create new folders and rename the old ones.
 Step 1: Get QB Tools Hub
 Close QuickBooks.
 Download the QuickBooks Tool Hub.
 Save the file.
 Open the QuickBooksToolHub.exe file.
 Follow the on-screen steps.
 Install the tool.
 Agree to the terms and conditions.
 When done, double-click on its icon.
 Open the Tool Hub.
 Log in to your computer.
 Ensure signing in as Administrator.
 Click on Start.
 Type gpedit.msc.
 After typing it, press Enter.
 Access the Computer Configuration segment.
 Select Administrative Templates.
 Double-click on Windows Components.
 Double-click on Windows Installer.
 Find Prohibit User Installs and double-click it to change its settings.
 Select Not Configured.
 Click OK to save.
 Click OK on any error prompts and then retry installing.
 Read Also:- How Do I Fix QuickBooks Error Code 7300?
 Step 1: Get QB Tools Hub
 Close QuickBooks.
 Download the QuickBooks Tool Hub.
 Save the file.
 Open the QuickBooksToolHub.exe file.
 Follow the on-screen steps.
 Install the tool.
 Agree to the terms and conditions.
 When done, double-click on its icon.
 Open the Tool Hub.
 After following the above steps to rectify the damaged installation and adjust
security settings manually, you can fix the Windows Installer is not
accessible error in QuickBooks.
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