Bootable USB won't working
Recently I tried to reinstall Debian in my Dell Inspiron system by making bootable USB. (Used both dd command and unetbootin) But my system doesn't considering it and booting direct to hard disk. (Of course, boot priority of USB is greater than HDD) .Result is same when tried with Arch also. But when I tried with some older versions of both, works perfectly. What's wrong with my system.
Thanks in advance.
Sent from my Android device with K-9 Mail. Please excuse my brevity.