My computer doesn't have a CD box. I saved the track in my documents but cannot use "open" for a .cda file and the Extract from CD option doesn't work either. Anybody could help?
I think you are attempting something "impossible" here! If your computer does not have a CD/DVD drive you cannot "Extract from CD" because no CD exists as far as Sound Forge and your PC are concerned! The program AND your computer can only extract from a real, physical, disc!
When you "copied" the contents of the CD to your pendrive on your old computer, your mention of .cda files means that you actually copied only the shortcut files which point to but are not the actual audio files(as John EB pointed out); you need to ensure you are copying the actual audio files but you cannot do this simply by "copy and paste" or "drag and drop" or any other "standard" Windows copy process. Instead, you will need to use a program that allows you to "rip" the audio from the original CD (on your old computer) and then transfer those files to your pendrive, and then open them on your new computer.
However, as John also pointed out, the ripping of files from a CD may be illegal in your country.
Dear Jeff, your answer was very helpful for my level of knowledge, thank you so much for taking the time to write all the detailed information.
In time, do you think I can use of the serial number of the Sound Forge in the computer that have a CD drive after having installed in the new computer without it?
I recall Magix allows SF Pro 11 to be registered and assigned to only two PCs at a time, for instance, if you have a desktop and laptop it can be registered and operational on both. It can be installed on additional PCs, but registered to only two at a time. The registration can be changed back and forth online though.. allegedly quick and easy, if you need it more than two computers. I would imagination, AS-12 is the same. To add to the confusion, prior to SF Pro-11, SF, Vegas, ect. could be installed, registered and operational on many, though you were only supposed to use one at any given time. After many installations SCS could lock it, but would unlock it on request, providing it was originally registered to you.