I use to have a razr it broke. I was using a different phone , then a friend gave me his razr. His carrier was att and mines tmobile. When i turn it on [with my sims card in] it says it needs some keynumber... ANY HELP!
Its sounds like your friend's razr is locked to your carrier.. In this case you have to unlock and not jailbreak.. You can get unlocking service from any vendors online like ProUnlocking.com Once unlocked you can access with any carrier