Error 1638: Another version of this product is already installed

Learn how to fix Error 1638: Another version of this product is already installed, in QuickBooks Desktop.

If you get this error, you might already have QuickBooks installed. All you have to do is find your version of QuickBooks and open it.

Find and open QuickBooks

1. Go to Start.
2. Select All Programs, then QuickBooks.
3. Select your QuickBooks version to open it.

If you don't see it:

1. On your keyboard, press Windows+R to open the Run command.
2. Enter Control Panel, then select OK.
3. Select Programs and Features. If Control Panel is in Category View, select Uninstall a Program.
4. In the list of programs, look for your QuickBooks version and open it.

If QuickBooks won't open:

Your QuickBooks program might have some errors. All you have to do is repair Quickbooks.

If you still have issues after the repair:

• Install QuickBooks Desktop again. This will create new folders for QuickBooks that can fix many problems you have with the program.
• If this doesn't work, install QuickBooks to a different directory folder and use a different location.

If you continue to get this Windows installer error and you can't install QuickBooks, you'll need to contact your IT professional or Microsoft for help. The issue might be related to registry entries for the Windows Installer.