Hi Lh,
Sorry for the delayed response.
As we have checked the account details using the email address you are logged into the forums, you have a perpetual license for Acrobat XI. If you purchase Acrobat for a single user or volume license, you can install it on maximum of two systems and can work on one at a time. Refer to this forum thread for more info: Acrobat Pro DC multiple computer installation
Do you have another email address associated with Acrobat 2017 purchase? If yes, you can share it via private message: How Do I Send Private Message
Let us know if you need any help.
Shivam