Serial Number

I had the Master Collection 3 installed on an old laptop. I brought the software through my school's program. A few years after, I bought the MC 4 upgrade through my school. Since, I have had to purchase a new computer and I tried to install the MC4 upgrade. I can only use a trail version for 30 days because I need the MC 3 serial number which I cannot find.

Is there a way to retrieve the serial number associated with my account or Adobe ID? I have the serial number for the MC suite 4 but it will not activate unless I enter the MC suite 3 serial number. Hence, I can only use it on a trail basis for 30 days.

Thank you in advance.