Originally Posted by
kpoeticg
When installing a dual-boot with Windows 7, the grub installer recognizes it as a Vista bootloader. When you choose Vista from the grub menu it will boot into your Windows 7 install. If you're not paying attention and install the grub bootloader to your MBR during an external HD install then you will need to have that same external HD connected when you want to boot back into Windows. Once you get back into windows you can use EasyBCD or any similar program to reconfigure your Master Boot Record so you can choose between your Windows Bootloader and GRUB when you power on your computer.