A file extension, or file name extension, is the letters immediately shown after the last period in a file name. For example, the file extension.txt has an extension of .txt. This extension allows the ...

I recently upgraded to Windows 8. Why do files no longer include letters after a period at the end of their names? I used to see file names that ended with .doc and .xls, and even longer names like ...

When you double-click on a file in Windows XP, the operating system will automatically open the file using a program that has been is associated with the file's extension. It is possible, though, to ...