Acrobat 7.0 standard won't let me activate after windows 10 install

I have Acrobat 7.0 Standard installed on my Windows 10 laptop, and formerly also on my Windows 7 desktop.  I uninstalled it on my desktop, then installed Windows 10.  Now it will not allow me to activate it on my (now Windows 10) desktop.  I used the built-in Acrobat uninstall process, including (supposedly) deactivation before abandoning Windows 7.  I need my Acrobat 7 to work, please!