How to compare Windows 7 iso against original?

Hello
I am in need of a windows 7 iso
could be pro, home, student, doesn't matter

apparently ms has removed this download from their website. I found many sites where this iso supposedly can be downloaded, some reputable like archive.org some not so reputable. in any case, I can never be sure that the iso has not been modified with keyloggers even if it's archive.org

coincidentally, I found an iso file on my computer called windows7
I don't recall downloading this, I don't know where it came from. maybe I downloaded it from somewhere, or maybe at some point I had a windows 7 cd and for some reason I decided to convert it to iso and save it. How can I know if this windows 7 iso is original or modified with viruses? can I somehow compare it against the original?

SIW2 said:

you can check the hash

for example
File: en_windows_7_professional_with_sp1_x64_dvd_u_676939.iso
SHA-1: 0bcfc54019ea175b1ee51f6d2b207a3d14dd2b58


File: en_windows_7_ultimate_with_sp1_x64_dvd_u_677332.iso
SHA-1: 36ae90defbad9d9539e649b193ae573b77a71c83

find the sha1 hash and search the ihternet for a match

english media refresh iso files sha1 list here
windows 7 SHA1 List . GitHub

Hi, thank you. Now the question is, how do I calculate the hash of the iso that I have?