What is the complete installation of Call of

Hello,

I needs some tips and solutions on how to install the SINGLE PLAYERmode of call of duty 4,because when i tried to install it the error message is: The DVD-rom could not be found,please insert cd click ok and restart PC. I already put the cd and nothing happens,i also created a virtual cd but still the error messages pops..Pls help me..
The multiplayer is working properly but only when i switch into single player there error message comes up The DVD-rom could not be found,please insert cd click ok and restart PC.