You are getting the error "Adobe PDF creation cannot continue because Acrobat is not activated" when you try to print via Adobe PDF printer. The reason it has an error is because you have been unable to activate Adobe Acrobat 8 or the activation has been corrupted. Here's how to fix it:
Try to close the current running process and run it again.
1. Press Control+Alt+Delete to open Windows Task Manager.
2. Click on the Processes tab. Then try to find the process Acrobat.exe and acrotray.exe, select each one at a time then right click on it and select End Process.
3. Once you have killed the two processes try to print again and see if you still have a problem.
Try to make the Adobe PDF Printer as the default printer.
1. Click on Start.
2. Click on Settings.
3. Click on Printers and Faxed.
4. Right click on Adboe PDF and select Set As Default.
For more information: http://kb2.adobe.com/cps/401/kb401043.html.