I can't do clean install for win 8.1 update 1 retail pro version,due to product key problem.i tried many keys still the same problem,key isn't valid,the key that i bought is working only when upgrading from windows 7 only,any help ??
you cannot use your real key for installation, google for windows 8.1 default installation keys and use the one according to the edition you are installing. then use your real key once you are in windows to activate