再インストール方法もしくはアップグレードについて

Hi 冬助,

I would try to answer all your questions one by one here.

So, about installing CS5.5 on Win 10, I would request you to check the system requirements mentioned on this link- Adobe Creative Suite 5.5 Master Collection: System Requirements​.

You have mentioned that your serial number is not working, if this is the 4th of 5th machine that you are trying to activate, its possible that activation count has exceeded. As per EULA, you may activate a  serial number on two machines, however, you cannot use both of them at the same time. For more information check- “Activation limit reached” or “Sign-in failed” error​.

If the serial number appears to be invalid, please check the information provided on this link- Error: "The serial number is not valid for this product" | Adobe Creative Suite​.  

If you are installing upgrade version of CS6, you would need a qualifying version serial number as well, for information on that check this link- Error: "This serial number is not for a qualifying product" | Adobe Creative Suite​.

Hopefully this answer all your questions. In order to assist you further any of the serial number issue, we would need to verify the details, we would need the serial number that you are trying to use. Please share the serial number via private message only.

Awaiting your response.

Thanks.