Computer file extensions and file help

Updated: 05/19/2017 by Computer Hope

.txtA computer file extension is commonly a three character addition that follows the name of a file. A few of the more common file extensions include EXE, DOC or DOCX, XLS, TXT, PDF, and MP3.

Tip: See our list of most common file types and file extensions for a complete list of file extensions broken down to categories.

Complete list of file extensions

Below is an alphabetical list of links to thousands of file extensions and brief descriptions currently listed on Computer Hope. For the file extension you are looking for, click the first letter of the file extension. For example, if you are looking for information about a .EXE file, click the letter E.

# | A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Computer file and file extension help

Reference Questions
Extension Our dictionary definition on file extensions and related links.
File Definition and information on a computer file.
CH000043 How to create file extensions longer than three characters.
CH000126 All Windows .exe files have changed association.
CH000128 In Windows when clicking a program get 'Open With Prompt'.
CH000164 Lost long file names when copying or moving files.
CH000209 Information on long file names.
CH000342 How to recover missing, lost, or deleted files.
CH000428 Changing a file extension.
CH000429 Viewing the contents of a file.
CH000430 Cyclic Redundancy Check or CRC error.
CH000486 Is it safe to delete .dll files?
CH000516 How do I view hidden files in Windows?
CH000572 How to associate a file with a program in Windows.
CH000573 How to view a computers file extension.
CH000769 How do I determine the size of a file or folder?
CH000771 How do I select or highlight multiple files?
CH000808 How do I compress or make files into one file?
CH001312 How do I create a computer file?
CH001314 How to create an empty or blank file.
CH001315 How do I list files on the computer?
CH001326 How do I count how many files are in a folder?
CH001356 How to create a CSV file.
CH001357 How to open a CSV file.
CH001359 How to create a text file.
CH001376 How to merge or combine multiple files.
CH001463 When I delete a file on my computer, where does it go?
CH001464 How do I delete hidden files?
CH001465 How do I hide a file in Windows?
CH001469 How to view the last modified date of a file.
CH001476 How do I move files?
CH001477 How do I copy, move, or rename files with a space in the name?
CH001562 How do I stop viewing hidden files in Windows?
CH001592 How do you copy files from one drive to another drive?
CH001695 How to save a document.
CH001696 Where should I save files?
CH001697 Why can I not save a file on my computer?
CH001708 What is the difference between a relative and absolute path?
CH001760 How to delete all files except files of a certain file extension.
CH001775 How to edit or rename a read-only file.
CH001789 What are the most common file types and file extensions?
CH001795 How to change the file attributes in Windows.
CH001819 How can I open an encrypted file or folder?
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