I downloaded Illustrator CS5.1 (for Mac) after purchasing it online. But during the install process it asks for a disk. How do I install the software without a disk? I thought everything I needed was in the downloaded files?
Yes, you only need your download. However, you may have other Adobe software on the system that you once installed using a disk and it messes with the AI installer. The best way to resolve such issues is to run the Creative Suite Cleaner Tool and start with a clean slate.