File Extensions Explained
File extensions have been used throughout the history of modern computing to quickly identify types of computer files. Traditionally, file extensions consist of three-characters ( such as “.doc” ) extended after the period in a file name. Newer technologies have begun using four-character extensions as well.Many extensions, like “.exe” for executable files and “.txt” for plain-text files, are universal, used by the operating system and all programs for files of that type. However, a significant and increasing amount of file extensions are specific to the program that uses them – “.docx” for Microsoft Office Word 2007 and 2010 documents, for example. Coming across an unknown file extension is fairly commonplace for most users.Discovering the proper file type associated with a file extension is an important part of investigating problems with files as well as issues inside the registry. File extensions can become improperly registered with the operating system and open in the wrong program when double-clicking on them. If you have a file that is not opening its associated program properly or is unreadable when opened, you might be experiencing this problem. It is important to know what exact type of file you are working with when investigating and correcting this kind of issue.All ‘retail’ and most ‘free’ registry cleaners include a large database of known file types to assist you in your troubleshooting efforts. Search the site for the file extension you’re looking for to get information on the type of file, what program opens it, and even whether or not the file extension can be used for malicious purposes. Following your software’s instructions will help you locate and solve any file or registry issues you might encounter.

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