1. Open Device Manager from the control panel.
2. Put your phone into serial mode so that the computer tries to load the HTC Modem Drivers.
3. Right click on HTC Modem and select properties
4. Click the "Update Driver" button
5. Select "Browse my computer for driver software" option
6. Select "Let me pick from a list of device drivers on my computer" (VERY IMPORTANT, Don't use the browse button here)
7. Select "Show All Devices" from the list and click "Next"
8. Select "Have Disk" Button
9. Now click "Browse" Button and browse to were you extracted the above files....and find the HtcUsbMdmV64.inf file.
10. Select it and select Open.
11. Click OK.
12. In the window you should see HTC USB Modem, Select it and click "Next"
13. Select "Yes" should you get a popup
This does not work.