I was able to download Photoshop for free through school (Pratt) and never had to enter a serial key. I know, I don't understand how it worked either.
It was downloadable on their website for some reason. They have since taken down the download.
I am running a 2011 MacBook Pro and am upgrading tomorrow to a MacBook Pro Retina.
I would like to be able to use Photoshop on my new computer (as I am still in school), but the serial number provided in System Info is only 20 digits as opposed to 24.
I know that you can enter your serial number on your My Adobe page, to be able to use the license on a new computer. But it doesn't accept my 20 digit serial number.
If Pratt provided you with the download, you would have to contact them and explain what happened. They should be able to give you this information or a new link.
If not, contact Adobe Customer Service. Contact Customer Care
…But it doesn't accept my 20 digit serial number.
All Adobe serial numbers are 24 digits.
The number shown by all installed Adobe applications on your computer are deliberately truncated to deter software piracy.