You need to unrar the file once it's downloaded then:
- Choose Start > Settings > Control Panel
Note: In Windows XP, choose Start > Control Panel - Double-click the Fonts folder.
- Choose File > Install New Font.
- Locate the fonts you want to install.
- In the Drives list, select the drive and the folder containing the fonts you want to install.
- In the Folders list, select a folder that contains the fonts you want to install. The fonts in the folder appear under List of Fonts.
- Select the fonts to install. To select more than one font, hold down the CTRL key and click each font.
- To copy the fonts to the Fonts folder, make sure the Copy fonts to the Fonts folder check box is selected.
Note: If installing fonts from a floppy disk or a CD-ROM, you should make sure this check box is selected. Otherwise, to use the fonts in your applications, you must always keep the disk in the disk drive. - Click OK to install the fonts.
That installs them to your PC and Photoshop (or similar) should automatically read them and use them.
**I have to add - that is the 'correct' way to add the fonts. I usually go to the control panel, double click on fonts then either drag and drop from the font file I've downloaded (and unrarred) or copy and paste. I find it easier that way (you need to be careful though as with most font packs, you'll find you get some fonts you already have - you need to tell the OS to write over existing files or ignore).
Hope that helps
