I too have CS6 on Windows 10 x64 however when you go to download that it says it is 32bit not 64.   I am still using Windows 10 and planning now to go to Windows 11.  After October Windows 10 will not be supported.  So, I am trying to find out how to deactivate and reinstall.  I did this once before, but that was a long time ago, and not sure what I did before.  I have Photoshop version 3 (even on floppy disks) versions 6, 7, CS, CS2, CS5, and CS6.  I think this is what I did last time.  I started the installation for version CS6 and when it asked for the serial number, I gave the CS5 number.  I just do not remember if that is what I did.  I looked and my disk and versions 6 and 7 say upgrade.   On versions CS, CS2, and CS5 I do not see the word upgrade on the disks.  What is the proper way to proceed?  I did not get a CD of version CS6, I believe I was given a link to download it.  I still have that download on my hard drive.   The file folder says I downloaded it in 2019.  If this file does not work how can I get a 64-bit version like I have now?  I have retired as a professional photographer so I do use the program very often, but I still might want to use it.

You’ve already entered your serial, correct? It discovers this is an upgrade serial and is now asking for the OTHER OLDER serial you upgraded from, that qualifies you to upgrade. It’s the only time “qualifying product” is used, and so it will NEVER show the current product.