File Names and Extensions

Under Windows 95/98, 2000, and XP file names can be up to 255 characters long. This allows the name of the file to accurately describe the information held in the file. With a name of Advisement Meeting Notes 11-13-2000.DOC, there is little doubt as to what the data file will contain. To tell different types of files apart, almost all files have what is called an extension (usually 3 characters long). This extension is separated from the name base with a period so in the example above, DOC is the extension.

As a rule, special characters such as extra periods, slashes, quotation marks and asterisks should be avoided in file names. The reason is that while some such characters are allowed, many are not. The exception is the dash character "-" which is useful for dates.

Since a file's extension tells how the file's contents are organized, care must be taken when changing the name of the file to not change the extension. If you try to do this, Windows will warn you that the file may become unusable. Don't change the extension unless you really know why you need to.