Paths of glory (or henceforth known as "POG") is a little editor for the Windows path environment variable. You can select folders from the folder explorer and add/remove them to/from the path by simply checking/unchecking a box. POG automatically remembers your previous path, so you can roll back changes easily.
POG needs the .NET 4 runtime installed and Administrator privileges. If it's not started as Administrator it can't write path values back into the system; instead it shows you a box with the path value, so you can at least copy/paste the value.
Known issues: Sometimes the check marks aren't in tune with the list of paths. I will probably not investigate this, since it's not really worth it. If you find any serious bugs, however, please let me know and I will fix them.
Download: Paths of glory 1.0