How can i activate window 7 ultimate i have product key error?

my laptop is dell inspiron 1545, 34 -bit,already was installed window home basic genuine with key. my friend again installed window 7 ultimate with key by formatting old homebasic. but here is message shows that ur window is not genuine. i put again window ultimate key no. then msj shows that key is not valid.i... show more my laptop is dell inspiron 1545, 34 -bit,already was installed window home basic genuine with key. my friend again installed window 7 ultimate with key by formatting old homebasic. but here is message shows that ur window is not genuine. i put again window ultimate key no. then msj shows that key is not valid.i downloaded window 7 loader key generator. i put all keys from generator but problem is still same. so wat i do for genuine activation.i frustrated abt applying so many methods from internet searching also.. plz help me if any expert here.i will be so thankful to u ..waiting
2 answers 2