I have purchased lightroom 5 at future shop with disc. I have registered the product online and just recently bought a macbook pro retina without a disc drive. I am trying to download this program with my serial number which was the only number that came with my program... I am finding this ridiculously difficult. I also read online to download the trial for 30 days and then it will ask for a serial number. I do not want to wait 30 days because I only have 30 days to return this computer if I cannot get lightroom 5 to work.
Unless I am misunderstanding you, the 30 day trial is just what you want. If you return the computer, you are better off not having LR registered on it.
Just consider both the computer and LR to be 30 day trials...if you keep the computer, then you can add your serial number at that time. If you have problems then, it can be sorted out and the LR catalogs you create will be intact for whatever license you decide on.
Once you have the trial installed you can input the serial number at any time. Once you input the serial number the program will no longer be a trial.
The trial software is the full program and is fully functional.
Only one thing that could cause a problem, make sure the disk/serial number you purchased is the full version and not an upgrade license. If it is the upgrade license you will also need a prior version license key.