My iPhone 4 was having some odd sound issues earlier, which randomly resolved themselves, but now it will not show up in Windows (XP) or iTunes (which I have the latest version of). This is not the first time I've had this happen. Usually tweaking the Apple Mobile USB device driver or restoring the phone by connecting it to my MacBook first fixes the problem. However, this time it's different. When I connect the phone to my PC, it prompts a USB Device Not Recognized message and appears in the Device Manager as an Unknown Device. There's no sign of the Apple driver anywhere. The phone also does not show up when I connect it to my MacBook, where normally iPhoto would launch upon connecting. I'm not sure what to do short of attempt a restore/recovery, but I really don't want to lose all my personal data (again). I've gone through all of Apple's support steps to no avail. Any help would be appreciated! Edit: Restarted the phone, sound issues are back. Primarily: there is no sound except for the ringer, notifications, and when using the phone. Key clicks and all app sounds are muted, and I can't adjust the volume by using the hardware buttons or the slider (there's not even a peg to slide) in the pop-up menu. In Sound settings, the ringer sounds when I adjust the volume there, and I do have the "Change with Buttons" option set to ON. Edit 2: Decided to try to follow these steps to hopefully restore the phone: http://support.apple.com/kb/ht1808 When I power down the phone (after sliding the red slider), the phone automatically starts back up again. Edit 3: Managed to get it into recovery mode. When attempting to restore, I got this message: Edit 4: Restarted the phone after two failed restore attempts, and it seems to be working for the moment, though the sound problem remains. Edit 5: Final edit before I walk away for the evening. Sounds work fine with headphones, but go silent again when I unplug the jack. No, the mute switch is not on. The audio lay-over doesn't even show up now when I press the hardware volume buttons unless the headphones are plugged in. Would still appreciate any advice!