This was one of my friends question about his BSNL dataone router/modem.
let us assume you can use ms dos for resetting the router, what command would you use? ms dos expired before routers were born, hence there is no command for the same in it. as far as i know, there are no command line prompts from resetting routers, regardless of the o/s.
on the other hand you can access your router through the `telnet’ command and then change the parameters but why take the trouble, when the reset button at the back is provided just for that?
So just see for the RESET button on back panel of your router keep pressing that button for 5sec and your routers all Factory settings will be restored, keep in mind all your stored passwords and user ID will be lost after doing that,so you must know how to setup a BSNL Broadband connection .
Note: If your have problem related to ADSL Link Look at this post, which will give your trick to make your ADSL Link constant.