License keys (serial numbers) work only with the then-current version of the product. To install older versions, you have to register the license key and then request a license file download. This process is explained here.
That said, student licenses may not work with sufficiently older versions. In most cases, the "compatibility issues" are simply a documentation issue or lack of testing on the part of the third-party software product.
For more help on licensing issues, you will need to file a support ticket at https://supporttickets.intel.com/
I did as suggested. Follow up question if I can. There doesn't appear to be an easy way to see if it works.
For example, I ended up initially selecting the trial period of 30 days to install the software. On creating then adding the license file, I got no indication that the license type had changed from trial to licensed, nor could I find anywhere that would tell be the type and/or expiry date of the license in use.
What way would I be able to see if the license file was accepted and the trial version is not still being used?
You want the "Intel Software Manager" which was installed along with the compiler. This tells you everything you want about a license, and is also the way to "upgrade" a trial license to a regular license.
Okay so that doesn't work.I get a message saying there are no licenses and that I need to refer to the account at the registration center. Clicking that link, entering the license key and email address used to make it brings up the message that the license is already registered. Bringing me full circle back to who do I know if this is working and which version am I using - trial or full?
Logging in to the site in the image below just lists the licenses listed under my username, it doesn't show me if the license is working on the machine it is installed on
I can't be of further help here - please file a ticket at the Intel Online Service Center https://supporttickets.intel.com/ and licensing experts will help you.