my usb port does not recognize my iphone lead

What kind of computer?

What operating system?

32 bit or 64 bit?

did you download the correct version of iTunes?

Are you using a USB port directly on the computer, or a hub?

If you have a Mac see: http://support.apple.com/kb/TS1591

For windows: http://support.apple.com/kb/TS1538

Windows? I'd follow the steps in this document:

http://support.apple.com/kb/ts1538

I'd also try a different USB port and cable, for testing.