When I insert my windows 98 boot disk it says A:/Please consult the docs that came with your sys if u needhelp

A:/ Please consult the doents that came with your system if you need help. I am using the windows 98 boot disk that came with my pc. My computer does not have a operating system on it. My computer is sorta old too I took off windows xp because I wanted to have windows 98 back. I also lust recently installed a new graphics card and a dvd drive not that youll need that info for anything.