Need serial number for CS5

I am trying to get the serial number for my cs5 so i can use photoshop on a new computer I bought. It is not listed on my account as one of my products. I tried the online chat and they could not help me. I tried to call and was told they do not offer phone support for my product. I believe I purchased it in 2011 but I honestly can't remember, I don't even remember if i purchased it from store or adobe online. I cannot find a disc box, receipts, or e-mails with serial number. On photoshop I tried Help>system info and only found a 20 number "serial number". What else can I do to get my serial number? I don't want to throw $100s away and I'm not really interested in the suscription. TIA!