"In 2011, during my school years, I purchased PS CS5 Extended for my MacBook. Recently, I acquired a new Windows laptop which doesn't have a DVD player. I've been attempting to download the app from your website, but I have a few concerns. I no longer have the student serial number as I'm no longer a student. Additionally, my new laptop runs on Windows, not Mac. Is it possible for me to use this app, which I purchased over a decade ago, on my new laptop?"
You will not be able to run a Mac version of CS5 on Windows.
When Adobe had both Mac and Windows versions, you could transfer your license to the other platform, but it had to be the current version and was not available once a new version was released. CS5 is 13 years old and Adobe is now subscription-only.