Error 4101: Another instance of setup is already running
Updated: 2/15/2013
Article ID: SLN12225
Error 4101: Another instance of setup is already running occurs when attempting to install TurboTax.
This could indicate that more than one copy of an installation program (such as the .NET 2.0 installer) is running.
Solution
To resolve this error, simply restart your computer and then install TurboTax.
If the error persists, restart your computer in Selective Startup mode and attempt to install TurboTax again.