I'd like to delete some fonts, but I'm afraid I'll remove some that Word needs. What fonts do I have to keep?

There is no practical limit to the number of fonts you can have on your system if you are running Windows 2000 or later (see below...).

But the more fonts you have, the longer it takes the system to load (though processor speed and amount of installed RAM are also issues here). So it is not a bad idea to rid yourself of fonts you know you will never use. There are a number of fonts, however, that you absolutely must or should not uninstall.

At the top of the list are any fonts used by Windows to display applications. In Control Panel | Display | Appearance | Advanced, find out what fonts are used in Windows title bars, menus, message boxes, and so on. Depending on the version of Windows and your own personalized settings, these may include MS Sans Serif, Tahoma, Trebuchet MS, and others. Windows and Word also need Marlett, which provides some of the graphic elements used in menus and toolbars, but you needn’t worry about this, as it is a Hidden font and so doesn't show up in the Fonts folder, anyway.

The “Windows core fonts” include Times New Roman, Arial, Courier New, Symbol, and Wingdings (plus their bold, italic, and bold italic variants where applicable). Most Windows programs (especially Word) expect to find these fonts installed. Times New Roman, Arial, and Courier New are used extensively in the built-in styles in Word 2003 and earlier, and some of the AutoCorrect entries depend on Wingdings or Symbol characters. Microsoft later introduced “Windows core fonts for the Web” that are used in many Web pages; in addition to Times New Roman and Arial, these are Andale Mono, Comic Sans MS, Georgia, Impact, Trebuchet MS, Verdana, and Webdings. The “C fonts” installed with Office 2007 (Calibri, Cambria, Candara, Consolas, Constantia, and Corbel) are also used extensively in that version of Word.

You will probably want to leave installed any fonts you have used in documents that you may need to access and print again. But if you move these fonts to another folder for safekeeping, they are easily reinstalled when needed. There are also third-party font managers that will install and uninstall fonts on the fly; most such applications store the fonts in sets that can be installed for particular projects.

Old Windows Font Limits

Even in earlier versions of Windows, the number is very large. According to the Microsoft Knowledge Base article “TrueType Font Limits in Windows 95/98/Me,” you can install a maximum of approximately 1000 TrueType fonts in Windows 95/98/Me.

The exact number of TrueType fonts you can install varies depending on the length of the TrueType font names and file names. The article goes on to say that font files are registered under a single key in the Registry, and a Registry key cannot exceed 64 KB in Windows 95. If font names average 20 characters in length and font file names average 10 characters in length, the maximum number of TrueType fonts you can install falls between 1000 and 1500.

If the font file is located in a folder other than the Fonts or System folder, the full path to the font is included in the Registry, using up more space in the key and reducing the number of fonts you can install. If you exceed the maximum number of fonts (that is, the maximum number of characters allotted for font names and file names), you will start losing fonts, and I’m not sure in what order they are deleted.