My system is running on ms dos and have forgotten the password.Anybody with a solution on how to overcome the problem.

I don't understand your question - is this a password that you are asked for as soon as you turn the PC on (i.e. a BIOS password)?

MS-DOS doesn't need a password to operate, so it's either a BIOS password before this loads or an application that runs on boot.

I refer to Ian Cunningham reply over my password thread.I think the system is asking for BIOS password which I don't know.How do I go about it ?.

You might be able to reset the BIOS by manually resetting the BIOS with the internal jumper pins (you'd need to read the motherboard manual to do this). Or, you'll need to ask whoever changed the password.