I downloaded Adobe Elements 2018. As I completed the purchase I noticed that I required 64-bit operation which is not available in Windows 7. I thought I had cancelled the MasterCard payment when I read that I required 64-bit operating system instead of 32-bit, but apparently I was too late. I now realize that it is all my fault for not reading the warnings carefully.
I can not install Adobe Elements 2018 because of this. Is it possible to obtain a refund on my MasterCard for this purchase since it can not be installed?
As far as I am aware, consumer law in many countries dictate that the buyer may return bought goods within a week, or so, and receive a refund. In some countries however this is not the case. So it depends where you live.
But you should be contacting Adobe support directly for a refund.