live boot usb wont boot with grub 2.0 installed on my kali linux sana 2.0

I have a Dell Inspiron 15 ruing kali linux 2.0 and ive had some issues with it that ive had to fix and ive decided that i want to try and run another linux distro such as arch or back box but when ever i load up a live boot usb that i have used before, grub wont detect the usb and my bios doesnt have the option to change the boot order. in the past some distros would boot up with legacy and others i would have to switch over to UEFI. i have done some research into my problem but everything that comes up is usually either they have to change the boot order or they are ruing a dual boot with windows from witch they delete grub from the mbr and reinstall another distro without grub on their device. Is there any way to fix this or should i just buy a new hd and install everything on there?