Transfer Serial Number from acrobat 9 to another computer

[keving64471975]

I am trying to Install acrobat 9 on a clients computer. They had acrobat 9 on there old laptop then a new laptop was purchased for them. We bought a separate license for acrobat DC 2015 but we continually were getting printing issues and uninstalling and reinstalling did not solve it. There is not the option to deactivate the old version on the previos laptop it is grayed out. Every valid serial number I enter on the new computer I get an invalid serial number. Any ideas how to solve this?

[kglad · Accepted solution]

if deactivate is grayed out, that installation is already deactivated.

if you see an invalid serial number message, the serial number and installation file don't match.  ie, either the serial number is wrong or the installation file is wrong.  Error: "The serial number is not valid for this product" | Adobe Creative Suite