Instead:
Elias clicked. The download bar crawled across the screen like a sluggish caterpillar.
: Be aware that CS3 is a 32-bit application and may not run on modern macOS versions (macOS Catalina or later) that strictly require 64-bit software. www.justanswer.com Useful Features of InDesign CS3
Even if you bypass these risks, CS3 will not install on macOS 10.15+ because Apple removed support for 32-bit applications. InDesign CS3 is a PowerPC/32-bit Intel app.
To run CS3, you would need a specific old Mac running . If you don’t have that specific vintage hardware, the download is useless.