Hi
You may not need to install XP before installing Windows 7 on your new hard drive.
Check the info in this link...
Link Removed - Not Found
I know someone who did the double installation of W7 successfully.
Once your have done the first install, about 20 minutes, don't activate it.
Start the process over and select upgrade and then when you finish the second time activate it and it will except you registration number.
Mike