Q: i reactivated my phone and it won't work now

"Activation server temporarily unavailable" means the phone was jailbroken, or the computer you are using to activate it was used to jailbreak some iOS device (not necessarily the phone with the problem).

When your friend set it up he hacked the phone. While it isn't illegal, it violates the contract with Apple and they will no longer honor the warranty or provide support for the phone. See: Unauthorized modification of iOS can cause security vulnerabilities, instability, shortened battery life, and other issu…