what is this term firmware & how to upgrade firmware.
thanx

Usually refers to low level code stored in EPROM/PROM, such as the BIOS on your motherboard. In order to upgrade it, you need two elements - the new firmware and what's usually known as 'flashing' software that will upload the new firmware into the EPROM/PROM. (EPROM = Erasable Programmable Read Only Memory)

It is the program inside the chips of the hardware, example : a CD ROM drive.

Usually, the upgrade is made booting on a special floppy with no memory drivers. The sites where you get the firmware usually give the necessary instructions to make the floppy.

I've always flashed firmwares booting in command line only (thus with memory drivers) with success, but it's not advised. It can leave the drive unusable. (I've got no floppy drive, and the sites don't give floppy images from which I could make a bootable CD ROM).

thanx u 2