i cannot find my serial number for my adobe acrobat 9 pro as a part of a creative suite 5 student and teacher edition german version

acrobat 9 is no longer secure and it is not compatible with newer os'es.  that said,

you have 3 ways to recover a serial number that you once had:

1. if you purchased from or registered with adobe (automatically done with cs6):,

    a. you can check your account, https://accounts.adobe.com

    b. you can check with adobe support* (be prepared to give the email address used when registering purchasing)

2. if your adobe program is installed on another computer you can recover its serial number from that computer, (win:) http://www.belarc.com/free_download.html, (mac:)  https://mac-product-key-finder.com/

3. http://helpx.adobe.com/x-productkb/global/find-serial-number.html

*

using a browser that allows popups and cookies,  contact adobe support during pst business hours by clicking here and, when available, click 'chat', http://helpx.adobe.com/x-productkb/global/service-ccm.html