To open a file you have two methods. You can either double click on a file's icon, which will open the program associated with that file, or you can open a program first and then use that program to open a file. Method one is the most popular because it is the easiest.
Almost all files have Icons attached to them. An icon is simply an image that is designed to represent a program and/or what a file does. For example: An icon with a Printer image might be representing a program that prints documents whereas an icon with a Paint Brush or Photograph image might be representing a painting program and/or be telling you the file is a photograph.
When you double click on a file's icon the program (i.e. Paint program) associated with the file (i.e. Photograph file) opens. So if you double click on a file (i.e. Test.txt) that has a NotePad icon attached to it (so you are really double clicking on the file's icon) the program NotePad will open and then display the text that is inside the file. If you opened a file (i.e. Test.jpg) that had a Paintbrush icon attached to it the program Paint would open and then display the picture/photo that is inside that file. Here are some common icons:
The traditional folder icon
When you create a new folder/sub-folder it will have the above folder image attached to it by default. The image can be changed with Windows 10 though.
The Microsoft Word 2016 icon
Double Clicking on a file with the above Microsoft Word icon attached to it opens the program called Microsoft Word 2016, which in turn opens the file and then displays its Text, Drawings and so on. The file's file name will end with the .docx file extension. Microsoft Word 2016 is meant for the creation of a Document file - A file that can contain Text, Pictures, Drawings and so on.
The Microsoft Excel 2016 icon
Double Clicking on a file with the above Microsoft Excel icon attached to it opens the program called Microsoft Excel 2016, which in turn opens the file and then displays its Accounting Data. The file's file name will end with the .xlsx file extension. Microsoft Excel 2016 is meant for the creation of an Accounts Data file, but it can contain other data too.
The Notepad icon
Double Clicking on a file with the above Notepad icon attached to it opens the program called Notepad, which in turn opens the file and then displays its Text. The file's file name will end with the .txt file extension. Notepad, as its name suggests, is a Text Editor that is meant primarily for the creation of a (smallish) Text file.
The Internet Explorer 11 icon
Double Clicking on a file with the above Internet Explorer 11 icon attached to it opens the program called Internet Explorer 11, which in turn opens the file and then displays its Internet Information (website/web page) contents. The file's file name will end with either the .htm or .html file extension. HTM and HTML files are made by a programmer for use with a website browser (such as Internet Explorer 11, Google Chrome or Fiefox) and therefore use with the Internet.
The Photograph icon
Double Clicking on a file with the above photograph icon attached to it opens the default Photograph Viewer program, which in turn opens the photograph file and then displays the actual Photograph. The file's file name will end with the .jpg file extension. Photograph files are normally created with a Digital Camera, WebCam, Mobile Phone, Photo Editor program, from a Scanner and so on.
The Paint icon
Double Clicking on a file with the above Paint icon attached to it opens the default Paint program, which in turn opens the picture file and then displays the Picture/Drawing/Photo. The file's file name will probably end with either the .jpg, .bmp, .tif, or .png file extension. Picture files are created with a Paint program (also known as an Image Editor), from a Scanner and so on.
The Microsoft Edge icon
Double Clicking on a file with the above Microsoft Edge icon attached to it opens the default program for the file type. Meaning: If the type of file is a PDF file, with the Microsoft Edge icon attached to it, the program called Microsft Edge will open which in turn will open the PDF file and displays its contents (i.e. Text, Web Page contents, PDF content, etc). Microsoft Edge is really meant for opening Internet files though, such as .html files, as it a replacement for Internet Explorer.
A Media icon
Double Clicking on a file with the above media icon attached to it opens the default (normal) Media Player, which in turn opens the media file and then plays the Audio/Video. The file's file name will probably end with either the .wmv, .avi, .mpg, .mp4, wma or .wav file extension. Audio/Video files are created with a Hardware Device and/or Software such as a Digital Camera, Camcorder, Webam, Movie Maker software and so on.
The above are just a few of the common Icon Types (Types of icon) - There are plenty more out there. Just remember what was said in the Folder & Files section though, because at the end of the day each file will only belong to one File Type (one type of file).
So now you know about opening a file with method one, by double clicking on a file's icon, let's look at method two. With method two you need to open (launch/execute) the text editor (program) called Notepad in order to then open a file. So begin by clicking on the START Menu button, using the left mouse button, to reveal the START Menu (Fig 1.1).
Fig 1.0 - Left click on the START Menu button to reveal the START Menu
When the START Menu appears (below) either press the DOWN ARROW (Down Cursor) keyboard key or scroll down the list of applications (programs) until you reach and highlight the menu-item called WINDOWS ACCESSORIES (above), which is actually a sub-menu. Clicking on it will reveal its sub-menu menu-items (Fig 1.2 below).
Fig 1.1 - The START Menu with its list of applications - Click on WINDOWS ACCESSORIES to continue
Fig 1.2 - Click on the NOTEPAD sub-menu menu-item to open the Notepad application
After clicking on the WINDOWS ACCESSORIES sub-menu you then need to move down its list of applications (sunb-menu menu-items), as you did above, in order to click on the sub-menu menu-item called NOTEPAD. So locate NOTEPAD and click on it (above). Doing so will open (launch/execute) the application (program / text editor) called Notepad.
When Notepad opens it starts with an empty edit box (the main white display area of its window) in which you can type something into it. Ideally, you type a Letter into it for example and then save that Letter as a file - See the How To Save A File section for more information.
Fig 1.3 - The program (text editor) called Notepad has been launched (executed/run)
On the other hand, you might want to open an existing file. Perhaps an half-written letter, an essay or whatever. In which case click on Notepad's FILE menu, to display its menu-items, and then select (left click on) the OPEN menu-item. After doing this an OPEN file requester will appear (Fig 1.5 below).
Fig 1.4 - Click on the FILE menu and then select the OPEN menu-item
To open a file, in notepad's case a TEXT file, you first need to locate/know which folder or sub-folder the file is inside. Locating a folder or sub-folder is done in one of three ways. Via the Address Bar's edit box, via the Navigation Pane or by double clicking through each folder - All of these methods have been exampled in the How To Save A File and Path Names Explained sections combined.
In this example (Fig 1.5 below) I will use the Navigation Pane (on the left-side of the file requester) to open a text file called Letter.txt that is inside the IMPORTANT sub-folder of my Storage (F:) flash drive folder. So to get inside the IMPORTANT sub-folder I first need to click directly on the Storage (F:) flash drive folder (shortcut link) or click on the light blue Folder Expansion (right_arow) button to the left-side of it. I have chosen to click on the Folder Expansion button.
Fig 1.5 - The file requester - Click on the Folder Expansion button to reveal the IMPORTANT sub-folder
NOTE: Clicking on the folder expansion button will only expand the navigation pane's folder view to reveal what sub-folders are inside the Storage (F:) flash drive folder, but it will not reveal them in the file requester's white display area whereas clicking on the shortcut link (the flash drive's folder name - Storage) will not expand the navigation pane's folder view to reveal what sub-folders are inside the Storage (F:) flash drive folder, but it will reveal them in the file requester's white display area.
After clicking on the Folder Expansion button within the navigation pane (above), to reveal the IMPORTANT sub-folder within the navigation pane only, the next step is to click on the IMPORTANT sub-folder (shortcut link) within the navigation pane to continue.
Fig 1.6 - Click on the IMPORTANT sub-folder (shortcut link) within the navigation pane to continue
After clicking on the IMPORTANT sub-folder (shortcut link) within the navigation pane you will be able to see the contents of the IMPORTANT sub-folder, which in this case is the Letter.txt file only. Fom this point there is only one more step you can take, and that is to open the Letter.txt file by either double clicking on it or by selecting (left clicking on) it first and then clicking on the OPEN button of the file requester. Either method will open the Letter.txt file and display its content (Fig 1.8 below).
Fig 1.7 - Select (left click on) the Letter.txt file and then click on the OPEN button to view the file's content
Fig 1.8 - The text (.txt) file called Letter is now open and viewable/editable within Notepad
As you can see. To open a file using the file requester is very very easy - Once you have navigated the folder view (i.e. the navigation pane) to the folder or sub-folder where the file to open is, you then either select that file and OPEN it or simply double click on the file. The complex part for some people is locating the file's folder or sub-folder via the OPEN file requester. That is why it is important to know about Folders & Files and their hierarchy.
After clicking on the OPEN button Notepad opens the text (.txt) file called Letter, reads the text inside it and then displays that text (Fig 1.8 above). It reads the text first so it knows how to display it properly. If the data is not text data, but picture data for example, it will not know how to display it properly and therefore just displays it as rubbish text.
Fig 1.9 - An example of Notepad displaying Photo Data as Text Data from an opened photo file called John.jpg
Going back to the file requester: You can change some of the elements on it, such as the File name edit box. It allows you to either type in an existing file name (no point, you would just click on a file name instead) or use its drop-down menu to select an existing file name, which already has the path name attached to it - The path name and file name can be different from the current path name and file name. In Fig 1.10 below I am going to open the Computer Lessons 2.txt text file that is inside the IMPORTANT sub-folder on the Data (D:) hard drive partition folder.
Fig 1.10 - You can change the file to open by using the FILE NAME drop-down menu
The other element you can change on the file requester is the Files of type, which is a drop-down menu. It has two menu-items to choose from. All Files and Text Documents (*.txt). All Files, when selected, will show you all the files in a given folder or sub-folder regardless if they are text files or not. From there you can open a file of any type, like a Photo file. But remember, a non-text file like a photo file will be displayed as rubbish text (Fig 1.10 above). So really, you should keep the File Of Type menu-item set to its default (normal) setting of Text Documents (*.txt) which only allows text files to be opened.
So what is the point of All Files? Well. Selecting All Files allows you to display (see) other text file types that have a different file extension - A text file with the file extension .INI for example, which is a text file for the system to read. Its text might contain system information like [XP] SP2=Installed, USERS 1. If you were using Wordpad instead of Notepad the default file extension would be .rtf (Rich Text Format), in which case you could change the file extension to .txt by selecting .txt from the drop-down menu. So a text editor can open other types of text file in other words.
Fig 1.11 - Notepad - Display Text Files Only / Open as a Text file
Fig 1.12 - Wordpad - Display Text Files Only / Open as a Text file
Fig 1.13 - Mirosoft Word 2016 - Display Text Files Only / Open as a Text file
Do not worry about the Encoding drop-down menu in Notepad (Fig 1.12). It should have ANSI selected, but if it does not (very unlikely) just click on its drop-down menu and then select the ANSI menu item.
So to recap, because a lot was explained above. Go to the FILE menu of an opened program (Paint program, Text Editor or whatever) and then select (click on) its OPEN menu-item. The OPEN file requester will then appear and you do as above to locate a file you want opening. Once you have located that file, using the OPEN file requester, either double click on the file or select it and then click on the OPEN button. Alternatively, if a file such as John.jpg is inside a folder/sub-folder, or on the desktop, for example simply double click on its (photograph) icon to open the program (i.e. Paint.exe) associated with that file.
One thing you should remember when opening files is that once one program is opened with one file, opening a second file might open a second window in that program - depending on the program. In other words: Notepad only opens one window to display one file's content (text). You would need to open a second Notepad program and file in order to display that second file's content whereas with a program like Microsoft Word 2016 it opens a separate window for each file it opens. So the more windows and files that are opened the more memory your computer is using.