I was wonder if I created a bootable usb version of windows 8.1 and ran/installed it from there, does that mean that it will delete my main hard drive? I am looking to dual boot. I want to keep my windows 7 on my main drive and go to windows 8.1 as needed via bootable usb. It's my first time so please help. When I install the windows version from the bootable usb, will it install on the USB or my real hard drive causing me to lose my main hardrive?