So, I was trying to upgrade to Windows 7 from XP... I download windows 7 to the hard drive and it stated cant install. So I made a USB bootable. Nothing!!! I looked at forums and googled and NOTHING!!! I kept getting NTLDR is missing. GRRRR 
I formatted my hard drive cleaned out XP and still the same thing. I was going CRAZY!!!! Finally I came across changing the BOOTMGR file in your bootable USB DRIVE into NTLDR. AND a mircle happens... IT BOOTS!!!
I formatted my hard drive cleaned out XP and still the same thing. I was going CRAZY!!!! Finally I came across changing the BOOTMGR file in your bootable USB DRIVE into NTLDR. AND a mircle happens... IT BOOTS!!! So all you have to do is: Change BOOTMGR into NTLDR
