Installing a font is not done "on the application" (in this case, GIMP 2.8), but done "in the system". Basically, you install the font in Windows, and once it is done, it will automatically apply to any word processing or text on just about any graphics application that contains text/compatible to it. It may not apply to some professional graphics applications (such an AutoCAD), but for general public use, you can safely say, that once the font is installed, it will work on pretty much all of your application.
This is the easiest way to do it:
Quoted from www.dafont.com
1. Download your font (I use free sites
www.dafont.com and
www.1000freefonts.com a lot). It is usually in the format of a zip folder, because one font can have different types of 'species'/versions, such as regular, italics, bold, condensed, medium, etc., depending on what font it is.
2. Unzip the files, until you see all "TrueType font files", ending with .txt extensions.
3. Before you install a font, make sure that
ALL of your applications (that contain text) are closed, so that they can be updated automatically. Installing fonts only takes effect when the application is update. In other words, for instance, when GIMP 2.8 is open and you are installing a font, GIMP will not take it, since it cannot update while it is open. It will update when you close it, then open the application back up.
4. Basically, your operating system determines how you should do it. For the newer system, the process has been simplified. Just click double-click each TrueType font file, then when the font opens, click the button on top that says "Install". Or, you can right-click on the TrueType font file, and click "Install".
5. Just as the above little note says, the older operating system requires a longer route, but it is not complicated. When you click "Install", you are prompted to browse the folder where you should save your font.
Fonts are always saved on your computer's local hard drive (usually called C:\). Windows XP and older operating system does not direct you to or save your font automatically to C:\Windows\Fonts, but the newer operating system does. Still, if you want to know what fonts you have on your computer, you go to that folder.
Once you install a font on your local hard drive, it will stay there 'forever' and applies to just about all applications, until you un-install it or your computer crashes. You do not have to re-install for every single application that you have.
Bear in mind though, that those non-standard fonts that you download manually, are not the standard fonts that come with an application. It means that if you change computer, the other computer may not have those fonts, since those fonts are not downloaded to the other computer.
Also, if you design something in GIMP (or type some text or use any downloadable font in any application), then you try to open that file on another computer that happens to not have that particular font, your file will not open (it will ask for a missing font). So watch out if you transfer a file or carry around a file in a flash drive and try to open it somewhere else that does not have the particular font. The best way to transfer a file - if you are not going to edit it - is by making a .jpg file out of the original file, or creating a .pdf file and embedding that font in the file.
