: Click Calculate to see the estimated size, then hit OK to begin the process. Premiere will copy all files into a new folder at your chosen destination. Key Considerations for CS4
Adobe Premiere Pro CS4 (released 2008) was a major rewrite for Adobe, introducing the modern tabbed panel interface. The "Portable" version is an unauthorized repack that runs directly from a folder or USB drive without touching the Windows Registry.
: Can be launched directly from a flash drive or external hard drive.
If you absolutely want to try it for nostalgia or offline legacy work:
Adobe never released an official portable version. These are cracked/pirated copies. Downloading CS4 Portable is software piracy. If you own an original CS4 license, you can theoretically make your own portable version (via tools like VMware ThinApp), but most users don't.