Error 1618: "Another installation is already in progress..."
Error 1618: Another installation is already in progress. Complete that installation before proceeding with this install may occur when installing or updating TurboTax
Cause and Solution
Windows or another program on your computer is installing updates.
All you need to do is wait for Windows to finish installing the updates before you update or install TurboTax.
Should the error persist, restart your computer and then install or update TurboTax.
See also Microsoft Support article How to troubleshoot problems that may occur when you install, uninstall, or upgrade a program on a Windows-based computer.