After considerable searching I was able to find out that both Vista and Windows 7 users are facing the same problem. I found some material for another Tata Indicom Modem Device built by Huawei which was able to solve the problem in this device made by EpiValley. Here are the steps you need to follow for making the USB device work:
- Install the client application completely as provided in the installation CD and plugin the Modem.
- You will find a folder named "drivers" in the installation location (C:\Program Files\EpiValley\TATA Indicom Dialer\drivers for default installation), copy this folder and save it on the desktop.
- Goto the device manager, under the section other devices, you will see something like this SIT_1x_USBmodem#1, right click and select update driver software.
- Now select the option Browse my computer for driver software and in the next option browse the location where you have saved the drivers folder, the drivers will be installed.
- Now you need to create the network manually. For this, goto network and sharing center and select the option Setup a new connection or network and then select connect to internet.
- The next screen will show connection options, select dial-up connection.
- The list of available modems will be shown, one of them will be SIT_1x_USBmodem#1, select this option.
- Following screen will ask for ISP information, phone number is #777, username is internet and password is internet, connection name can be anything you like to call it like Tata Indicom.
- Press connect and you are done. Everytime you need to browse internet, just connect your device and this connection will appear under available connections.