It's illegal to modify the .exe content, however if you don't want to use the original CD I suggest making a backup of it and using that instead. I'm pretty sure that's legal to do if you don't distribute the copy.
You need learn how to use ---->www.google.com<----- The all mighty search. Just letting you know, that's why no one is replying. The CD is there for a reason.
There is an application (sorry the name escapes me) that takes some of your hard drive and makes it a virtual CD-ROM drive. You can then copy the contens of the CD on to this partition of your drive and you will no longer need the CD. If you google this you will find probably a few apps that can do this.