@ cckc
As you experienced, I can also personally confirm that having a USB device (even as simple as a thumb drive) plugged in when launching TurboTax can confuse TurboTax and cause it to ask for an activation code. I had no trouble launching TurboTax for weeks. Then yesterday I forgot that I had a USB thumb drive plugged in, and TurboTax asked for activation. As soon as I removed the thumb drive, I was able to launch TurboTax normally without any request for activation.
It's common enough that I tell users that solution first. TurboTax is detecting a USB device as a change in system configuration and thinks it is a different installation.
It may also work the other way around, too, but I have no way to test it. For example, if one had a USB device plugged in when TurboTax was first installed, it might recognize the absence of the USB device as a system change.
