Probably. Did you use your d'load to create a disk/USB drive? If so I would simply clean install W8 and try to activate it by performing a 'Refresh' immediately after installation.(Leave your Installation Media in place.) if it fails to activate...
1) Press Windows key + R, then type: slui.exe 4
2) Next press the 'ENTER' key
3) Select your 'Country' from the list.
4) Choose the 'Phone Activation' option.
5) Stay on the phone (do not select/press any options) and wait for a person to help you with activation.
6) Explain your problem clearly to the support person.
http://support.microsoft.com/kb/950929/en-us