There are mainly two release types. This page explains the difference between them.
The standalone zip file contains the SweetFX program, plus the SweetFX Configurator exe file. This will work on most computers with updated 4.0 .NET runtime installed. The user just need to unpack the file, and run the executable. To uninstall it’s just to delete the folder.
This version comes with an installer that verifies that all dependencies are on the system, squirrels the files into .. somewhere on the file system, sets up shortcut in the start menu, and adds an Uninstall entry in the Windows system.
I usually recommend the Standalone version, simply because it’s easier to work with.
Experimental web installer
I have added an experimental Web installer to the site, which you can find here. It’s more or less the same version as the installer, only it’s set to install from a web directory instead of a local directory.