If you installed the Non-Creative Cloud trial version, you should be able to enter your serial number from your boxed version and go.
If you installed the Creative Cloud trial version, you would need to uninstall that version then install the non-CC version and enter your serial number when prompted.
Thank you for your prompt answer.
I am new to the Adobe Creative Cloud and Lightroom and I do not remember which trial version I installed.
That being the case, is it advisable to uninstall what I have and install the new CD version?
When you start the trial version, on that initial screen, if there is an option to indicate that you have a serial number you can choose that option and enter the serial number. If you don't see that option then you probably installed the creative cloud version. You can uninstall whatever you have installed and then install from the disk. But you will have to do an update immediately if you want to have the most recent version. If you can enter your serial number into the trial version that you have installed then you can bypass having to do the update.