I'm having an issue where my HTC Thunderbolt is not recognized by my PC any longer. All of a sudden, any computer i tried to plug the device into, wouldn't detect the phone. When plugging my phone in, it pops up an error message with "USB Device not Recognized." In the device manager, the phone shows up as Unknown Device. I have tried this on 3 different pc's, using 3 different data cables. No USB symbol displays on the taskbar of the phone when I plug it in, however, it does charge. When i drag the notification bar down, there is nothing there. What I have tried: Changing data cables. Using another PC. Uninstalling device drivers and letting windows re-detect and install. Downloaded HTC Sync and ran it after uninstalling drivers again and re-plugging the phone. Manually telling the system where the drivers are (Windows says the drivers are not compatible with my device, even though they work for another htc thunderbolt). Changed different Connection settings on the phone, such as USB Debuggin on/off, and changing it to HTC Sync Mode, Charge Only, Disk Drive, etc Mounted and unmounted SD Card in the phone settings. Resetting to factory settings.