I've tried to install iOS 5 on my iPhone 4, but it keeps giving me an "unknown error (14)".
Can someone help me with this? I won't have time to pass by the apple store to get this fixed for another week.
This sounds like a typical problem if your hosts file is blocking Apple's servers (usually because you either manually edited them at some point to jailbreak a phone or ran Tiny Umbrella and had it set to point servers to Cydia on exit.
If you did use Tiny Umbrella, the easiest solution is to turn the software back on, uncheck the "Set servers to Cydia on Exit" option, and then exit the program. This should cause it to comment out those lines in your host file.