HTC has just released a new set of drivers for Microsoft Windows Vista OS. This drivers allows you to use your Windows Mobile based HTC TyTN GSM Pocket PC device as a wireless modem for your desktop computer. The package consists of two files- wlphonecv.cat & USBMDM.inf.

1) Download and extract the package to a folder on your computer.
2) Goto Start—>Programs—>Modem Link and open the Modem Link program on your Pocket PC
3) Select the USB option and click Activate
4) Once you connect the mobile device to your Vista based computer, it will prompt for the drivers. Select the option to manually install the driver.
5) Browse to the folder where you extracted the two driver files in the New Hardware Wizard and reboot your computer

Download the drivers here