New
#41
OK, I wasn't sure how far you got. You can leave it blank and still install. You then have 30 days to enter a valid product code. If your product code is being rejected during the install its either typed incorrectly or not the right code for the version you are installing. As an example you can't install Pro and try to enter a Home premium product code. I'm not saying thats what your doing, I'm just saying that is one thing that can cause your product code to be rejected. Double check to make sure you are not typing say an 8 when it should be a B or maybe an O instead of a Q or vise versa. At that point in the install (as far as I know) windows has no way of knowing if that code has been used before or on another PC. That only comes into play when you try to activate windows.