There are a number of ways to connect the HTC mobile phone to your computer. The most common method is to use the HTC Sync software. This you can download below from the HTC website. There are other drivers for the HTC such as the HTC MTP driver as well as the HTC USB modem driver which is also on this website. The HTC Sync software is the easiest to connect the HTC phone to the computer.
HTC U Ultra Drivers
You can find the software below which will take you the the HTC website where you can download the driver. Its a large software package of about 150Mb so you need to check your bandwidth if you are paying for internet traffic. First thing to do is to disconnect your mobile phone from your computer. Uninstall the older driver or software from your computer. Download and install the HTC Snyc driver and then reboot your computer for it to take effect. Then connect your HTC phone to the computer.