The "Portable and Installable Edition" typically refers to two distinct methods of utilizing the software: Altium Designer 13 Portable Edition Guide | PDF - Scribd
Altium a portable version of Designer 13.1.2. Altium Designer is a resource-heavy application that installs system drivers (for USB licensing dongles, printer drivers for Gerber export, and integration with Windows Explorer). A true portable app — one that runs from a USB stick without touching the registry or system folders — is technically nearly impossible for a tool of this complexity.