You do not need to input all X's. The problem you guys are having is that you are trying to "skip" it. That's not possible. You need to let the product key process run. When it runs it will pick up the key in the BIOS. Specifing for it to never run or to show errors will cause it to error out. Just leave the Key field blank and tell it to ALWAYS show. If there's a BIOS key to be found you will never see the CD Key window, it will in fact proceed unattended. <UserData> <ProductKey> <Key></Key> <WillShowUI>Always</WillShowUI> </ProductKey> <AcceptEula>true</AcceptEula> </UserData> Removing ProductKey altogether as the OP has done will also throw out an error.