Deactivation on old computer / Registration on new computer

I have installed acrobat pro XI on a new computer following deactivating my serial number on a previous computer.

Acrobat is now informing me that the program is registered on two computers, even though I deactivated it on the previous one.

I no longer have access to the previous computer.

Is there a way the serial numbers can be deactivated from all machines in order to enable me to register it on my new computer?

Look forward to your responses.