Guide to Use Any Sim Card in BSNL/MTNL Teracom 3G USB Data Cards

Requirements:
Data Card (BSNL/MTNL Teracom LW 272 or LW 273)
BSNL/MTNL SIM Card
Other Operator's SIM Card

How To?
Connect the Data Card with BSNL/MTNL SIM Card inserted to the system & install the software.
Let the System install the drivers for the Hardware.
After completition Restart the PC.

After Restart Close the application which modem installed if it is running, Go to the installed directory of the application which
usually looks like this "C:\Program Files\BSNL 3G Data Card\BSNL 3G\BSNL 3G.exe " and change it's file type from executable
to something like 'BSNL 3G.Backup'. (Note: It may be different in case of MTNL data card).

Go to Control Panel > Select Phone & Modems > Select the Required Modem (e.g. HSPA DataCard.) > Go to Properties of
that Modem > Select Advance TAB & insert Extra Initialization Command (AT+CGDCONT=1, "IP", "APN"). Press OK. (Replace
the "APN" with your new Sim Card Mobile Operator's APN). You can find more information on this below.

Now Select Network Connections in Control Panel.
Click on "Create new Network".
A wizard will start up. Click next.
Select "Connect to Internet". Click next.
Select "Set up my connection manually". Click next.
Select "Connect using a Dial-up Modem". Click next.
Select Your Modem. Click next.
ISP Name: (Any name could be written). Click next.
Phone Number: *99#. Click next.
Replace the "*99#" with your Mobile Operator Phone Number. You can find this information below.
Leave User Name, Password, and Confirm Password fields blank. Click next.
Click on "Add a shortcut to Desktop". Click on Finish.

Disconnect the data card and replace the BSNL/MTNL SIM Card with the mobile operator's SIM Card of which you entered
the APN before.
Connect the data card again and wait for the green light to glow.
Now you can connect to the internet by double clicking the shortcut of the new dial-up connection we made.

GPRS SETTINGS OF ALL OPERATORS.
Reliance
APN: rcomnet
Access Number: *99#
Aircel
APN: aircelgprs
Access Number: *99***1#
Idea
APN: internet
Access Number: *99#
Docomo
APN: TATA.DOCOMO.INTERNET
Access Number: *99#
Airtel
APN: airtelgprs.com
Access Number: *99#
BSNL 3G
APN: bsnlnet
Access Number: *99#
BSNL 2G
APN: bsnlnet
Access Number: *99#
MTNL 3G
Postpaid: APN: mtnl3g
Prepaid APN: pps3g
Access Number: *99#
Vodafone
APN: Vodafone www
Access Number: *99#

This is completely different procedure than which are posted before in this forum.

If you like my effort then do post replies as it encourges me to do some more good work like this.