First you should install the product key using slmgr.vbs Assume you are in system32 dir open a command prompt session and type cscript slmgr.vbs -ipk xxxxx-xxxxx-... then you should install the corresponding Cert based on your machine which would be HP cert using cscript slmgr.vbs -ilc HPCert... you can use 7loader by Daz in advanced mode which will do all of these ... Good Luck