a few days ago, i bought a second-hand iPhone4 iOS 5.0.1.
It's completely original, no simlock or whatsoever.
When I connect the device to my computer (running on Windows7), Windows displays a notification: Unknown Device. Windows doesn't recognize my iPhone.
The cable or usb-ports aren't the problem (I tried 4 different cables and different laptops).
I tried to completely wipe all of my Apple-software from my computer and reinstall it, no success.
Putting the iPhone in recovery-mode or DFU-mode is pointless, since iTunes doesn't recognize my iPhone.
Also tried restoring the device to it's original settings, still the same result.
I connected the iPhone to a computer which never had any Apple-software installed on it, but it also didn't recognize my phone.
Charging through the socket works fine.
My old iPhone 3G hasn't got any of this problems.
The former owner never had any of these problems.
Maybe my problem has something to do with the fact the iPhone was connected with another laptop or something like that? I really don't know.
Any help, please?
Thank you! (sorry for my cheesy English)