How to fix Error 1601, 1603, and 1642

Learn what to do if you see these errors in QuickBooks Desktop.

If you see any of the following messages when you install or update QuickBooks, we'll help you get on your way.

• Error 1601: Windows Installer is not accessible
• Error 1603: There was a problem installing Microsoft .NET Framework [version]
• Error 1603: The update installer has encountered an internal error
• Error 1642: Error installing Microsoft .NET Framework when installing QuickBooks

Fix errors when you update QuickBooks Desktop

These errors mean there's an issue with the install or update file you're using. To fix them, install QuickBooks again to refresh your system files.