Installing iOS7 beta instalment?

Basically i was trying to put the ios7 firmware on my iPhone 5 without restoring it and it said "the firmware is not available" so I was wondering if its just because it wasn't restored or whether it just won't work

Ios 7 hasn't been released.
its in beta testing for devs.
if your not a dev and install it, your phone will be disabled on or before july 22nd.