I'm currently using a Dell Inspiron 3520 laptop with Windows 8 on it. I have an external hard drive from a Windows 7 desktop. It recognizes the external hdd right away and I can access it but I can't figure out how to boot Windows 7 as the primary. I've tried changing boot order in bios but I've had no luck as it still boots Windows 8 first. Is there a way to use the Windows 7 as the primary drive or could someone teach me about dual booting? Even a way to temporarly turn off the Windows 8 hard drive will work. I just need to access the Windows 7 hard drive without having to navigate through program files to have to open something. Any ideas?