1. While phone is connected, go in to your device manager and locate where your handset is. Usually under Android phone or Portable Devices. Once there right click on the device and uninstall.
2. Now disconnect phone and reinstall HTC sync or the HTC Drivers if you have them separately.
(If your phone was not listed in device manager than uninstall any drivers you have in your programs via control panel and follow step 2)
*Note* If you are in fact installing the drivers by way of HTC sync then after installation is complete, remember to remove HTC sync from your programs via control panel, your HTC Drivers will not be touched.
The more you sweat in training the less you bleed in battle