Portable vs Installed: When to Pick Which

A portable app runs from a folder without touching the registry, Program Files, or the user profile in ways that matter. An installed app runs from Program Files and stores its settings under AppData. Both work; the choice matters more in some situations than others.

For shared machines, portable apps win. The user profile stays clean, permissions are simpler, and moving between machines is a folder copy. For a laptop that is yours and only yours, an installed app integrates better with Windows features like file associations, protocol handlers, and jump-list customization.

The exception on both sides is the browser. Even a portable browser cannot escape the OS-level default-app registration, and even an installed browser can be told to keep its profile in a folder you choose. The distinction blurs on the edge cases.

A rule of thumb: portable when the app is a single-purpose utility you might use once a week from a USB stick; installed when the app is central to your daily workflow and you want the OS to know about it.

Further reading: Wikipedia — PDF format overview.