When attempting to install QuickBooks Desktop, the following error is occurs:
Error 1638: Another version of this product is already installed...
- Check to see if QuickBooks Desktop is already installed.
- Go to Start > Control Panel > Add/Remove Programs.
- If the version of QuickBooks Desktop you are installing is listed here, it is currently installed.
- If QuickBooks Desktop is installed already, you can open the program and use it:
- Go to Start > All Programs > QuickBooks
- Click the version of QuickBooks Desktop you wish to use
- If you can not open the program, Repair QuickBooks.
- If repair is unsuccessful, perform a Reinstall using a clean install.
- If unable to uninstall the program, look up the error message you are receiving when attempting to uninstall on our QuickBooks Support website (US, Canada or UK)
- If all of the steps above fail to uninstall the program, use the Program Install and Uninstall troubleshooter to remove QuickBooks
- If none of the above steps resolve the issue, try installing QuickBooks to a different directory folder