my back up games keep asking for a cd.... why is this???

[cjl64]

I made a back up of C&C generals with alcohol 120% and installed with the back up to test it and it does install. But it ask for a cd even though the right back up is in the cd tray. What can i do???? i have tried daemon tools but find that only works with an iso on the hard drive and thats no good because iso's take up way to much space on the hard drive. Is there any way i can just make a 1:1 copy with out the head ache? I have been fighting with this back up stuff for a month now and really need any help i can get at this point. Thanks