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#11
If your bootable ISO is not corrupted, and your Windows 7 for native burning is not corrupted, I see no reason why and how the burnt CD/DVD can become non-bootable.
If you do want to check the veracity of the above statement, then do as follows.
1. Create a system image with any imaging program of your choice and keep it aside,so that you can restore it later to the present state. (Whenever I make a crucial image, I always restore from that image immediately and check to make sure it is in no way corrupted and fail on me anytime later when I want to use it.)
2. Make a clean install of your Windows 7. Download any small bootable ISO and burn it using the native burner and report whether it is bootable or not.
While trying to boot from the CD/DVD enter the boot menu (by pressing F11 or F12 or any other key as indicated by your motherboard) and select "boot from CD/DVD."
Assuming that everything you do and have is correct is no way to resolve a problem and one has to do a little bit of research on the lines indicated above on his own before putting out any conclusions or blaming something faulty. In the present instance majority of users have no problems burning a bootable CD with Windows native burner.
My post may sound harsh but really nothing like it. I am only putting out my mind having seen all your posts.:)