Unable to activate serial number

I am trying to install Adobe Acrobat 9.0 Standard on a new laptop running Widows 10 Pro & the Serial Number is being rejected.  Is this because Acrobat 9 does not operate under Windows 10 Pro, or would it be because I did not deactivate the application on an old computer as yet (old computer is not connected to the internet & so I am not sure how to deactivate it)?  If down to Windows 10 Pro issues, is it possible to upgrade the product and if so, which product should I upgrade to & how do I go about doing that?  Just a heads up that I have tried adding the Serial Number to a new Adobe ID that I have created & I get a message saying "We're sorry. Something seems to be wrong on our end. Please try again later. If this continues to fail, please contact Customer Support." - Can anyone help please?