The program does not need an installer; simply copy the files to a permanent location and run spc.exe.
When you first run the program you will get a little message warning you that the program makes changes to your registry and telling you about the log file (see below) in case you get into trouble. After you save the settings once, you won't see this warning again.
The combo box shows two different path variables you can modify, the Local Path and the System Path; the System Path is normally the one you want to modify.
Directories currently on the System Path are shown with a check mark. Invalid directories are colored in red. Changed entries that have not yet been saved are shown in green.
To disable a directory, simply uncheck it. This will cause the directory to be physically removed from the environment registry variable, but it will still show up in the list because the program remembers it.
You can access a context menu of additional options that can be performed on entries using the right-click mouse button. You can drag and drop folders onto the window to add the folder to the bottom of the path.
Right click on an entry for more options, or hold the control key whlie dragging to reorder items.
Note that no changes are actually made until you hit the Save button.