What do you do when your computer says "Bad command or file name"?

Then write the correct command or syntax.

This generally happens when a computer boots up and your boot.ini file is corrupt or missing. The solution to this is removing the new software that you have installed by booting into the safe mode and uninstalling the software...

i will again give a command in a better way to a computer.

nothing to worry about just write down the correct file name.

I haven't come across such thing till date, and if the computer says so then I may try to correct it

Try for another solution.

In such case i'm always looking out for the solutions for that kind of problem.