[Installation was giving CompareExchange128 error until I installed an unofficial bios microcode, now my games crash on 64bit Windows 10]

My CPU is an LGA 775 modded Xeon E5450, and my motherboard is a Gigabyte GA-P43-ES3G.

Normally I could not install 64 bit Windows 10 or 8 on this machine, because it gives CompareExchange128 error.

I tried the microcode for my motherboard that I found here to solve this problem first, I could install 64 bit Windows 10 but it didn't allow me to play my games at all:

https://xeon771to775biosmod.blogspot.com/2018/08/gigabyte-ga-p43-es3g-xeon-microcode.html

Then I tried the microcode for my motherboard that I found here, I could install 64 bit Windows 10 and play my games but they have been crashing too much compared to when I was playing them on Windows 7:

http://tanieprocesory.pl/en/bios2-2/

I mostly play Rocket League and it may as well be specific to the games that I play especially since 2 of my RAM sticks stopped functioning normally before all this and I have been on only 4GB of RAM. So today another 4GB of RAM will arrive and I'll see how it goes but now I think that it may be about the unofficial bios code that I have been using after all.

Do you know of another way to install and use 64 bit Windows 10 on a PC like mine ?

[What are the differences between the ISOs that can be found on the software and other places ? Can I get a download link ?]

What are the differences between ISOs I can find here,

https://thehiddenbay.com/search/windows 7/1/99/300

here,

https://archive.org/search.php?query=windows 7

or the ISOs that become available during first days of the months on HeiDoc.net Windows ISO Downloader ?

I prefer 64 bit Ultimate English and Turkish can also be useful, which do you think is the best ? Can I get a link to that ?

I need it legacy BIOS compatible by the way.