No you don't need to call Flexi, you can uninstall and install the program as needed.
But, if it was me, I would leave it on the old
computer till you install it on the new
computer and get the bugs out, if any. You should have a dongle, which will only allow it to be used on the
computer the dongle is plugged in to.
You will need your dongle numbers to type in during installation, so before uninstalling anything, make sure you have the right stuff. If it's a usb dongle, you will need the hasp driver also.
I think you can have the program loaded on more than one
computer, but only use it on one
computer at a time. This is where the dongle comes in. You can unplug it from one, and plug it in the other.
I got a new
computer several months ago. Left my old
computer loaded with all the programs in case of a lightening strike or other catastrophe. But again...I'm only using it on one
computer at a time.