help for bsnl 3g data card unlock LW 273

I recently purshased this usb device for internet but when i insert other sim, it says invalid sim.
Anybody here pls help to to unlock this Teracom device.
Answer #1
Try here…
http://www.forum.shaarpmind.com/showthread.php/293794-BSNL-Teracom-LW272-LW273-Unlock-Software
or ebay.
Answer #2
it did’t helped,
please any other suggetion..?
Answer #3
Best method go to your nearest cell phone shop and pay ~$6 technician will do that job.
if you have enough time & eager to have a data card repair shop then
1. Normally network providers will sell their data cards with sim locked to their network only.
2. You can’t use other sim & sometimes even you can’t use same network sim except comes with your data card.
3. datacard or modem should be unlocked first either by downgrading or upgrading with relevant firmware and correct flash code(Not all possible with this trick)
4. You should have a mobile partner software called as dash board to access all networks with appropriate apn & access settings.
5. Getting correct flash code & firmware is hard (during firmware up-gradation your modem should not be removed & uninterrupted power required)
still if you are interested try
http://forum.gsmhosting.com/vbb/index.php
http://3g-huawei.clan.su this is russian translate into english with google translate.
http://www.wrock.org
http://www.modemunlock.com/huawei-code-calculator
www.dc-unlocker.com
Best of luck