Star Wars: Knights of the Old Republic 2 Cheats
This probably means that you are logged on to the computer with an account that does not have administrative privilages, and / or the file has been set as read only.
If it is the last reason, you can right mouse click on the file name (while it is not open in your editor) and choose properties from the context menu that pops up, then in the properties box that comes up, untick read only.
For the first answer, you either need to have your logon account elevated to administrator, or log in via an account that already has administrative privilages.
This may be problematic if you do not actually 'own' the computer you are playing on, as you will have to ask the person who controls it, to let you do one or the other, and with good reason they may not want to, as it will compromise their system security.