My computer is showing an exclamation point next to it. Shows an unknown device?

No new devices plugged in. Tried to sync iphone (worked previously) it failed(showed as camera in devices does not appear in itunes. Unplugged usb and iphone, restarted computer and now it shows an exclamation point and an unknown device next to pc!

The exclamation point means that the device driver is missing. I found an Apple support article that should put you on the right path.

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

Remove and reinstall the drivers from device manager…

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