We are also unable to activate our Windows 8 Enterprise x64. Fresh install.
We are getting error:
Windows couldn’t be activated
Go to Control Panel to learn about other ways to activate.
Error code: 0x8007007B
Error description: The filename, directory name, or volume label syntax is incorrect.
Got it to work by doing the following:
Run an elevated CMD window and execute slmgr.vbs -ipk “YOUR_PRODUCT_KEY”. Now you can use the activation wizard found in the control panel.
Source : http://social.technet.microsoft.com/Forums/en-US/w8itproinstall/thread/d469845e-38fb-4ba8-9161-8e42ec12044b