All types of files in Windows OS are associated with certain applications. This means that when accessing a particular file, it will automatically start exactly with the program that is assigned to it in the registry (for example, documents with the .doc extension are opened by Microsoft Office). However, if data from the registry is changed or damaged, files may not open correctly, that is, not with the means that were installed behind them by default.
A similar situation can be observed with a system failure or virus infection. In the Windows 7 operating system, there are several standard ways to restore associations:
- using the "Open with" command;
- through the recovery archive;
- via command line.
There are also additional resources that are simply indispensable in cases where the built-in methods of resuscitation are not suitable.
Before you can repair file associations in Windows 7, you need to check your computer for malware.
Otherwise, the solution to the problem will be temporary.
Using the "Open With" feature
This method of returning default value associations is considered the simplest. However, for its successful execution, the user must know which application is responsible for opening a particular document.
Restoring default associations is done as follows:
Restoring the association in this way is not suitable for .exe files, shortcuts and folders.
Applying the Registry Archive
If you have trouble opening .exe executables, managed applications.cpl, .msi installers, shortcuts, or folders normally, you can restore them by downloading the special Windows ResetFileAssociations.zip archive. Each version of the operating system has its own archive, that is, an application downloaded for Vista will not work for Windows 7, etc.
The recovery order will be as follows:
To change data in the registry, you must have administrator rights.
Another way out of this situation is to download a backup copy of the Windows registry saved on your computer (backup document). Saving the registry is a very useful feature that allows you to get rid of many problems associated with system failures and virus attacks.
To back up the registry, you must:
If you need to make any changes to the registry (for example, restore the default file associations), you should go to the folder with the saved backup and run the executable file.
Restoring associations using the command line
This method allows you to restore file association in Windows with any extension. For this you need:
Using additional software
In addition to the methods of restoring associations built into the Windows system, there is additional software that allows you to solve this problem. One of these programs is the File Association Fixer, which is able to revive the 18 most popular associations. It doesn't need installation. It is enough to open the file with the .exe extension, select the required associations and click Fix Selected. 
Since the standard functionality is provided for playing popular types of video, audio, text and some other files in the Windows system, it was the standard programs of the system that were initially set by default to open the file types they support when double-clicking on these files. But as third-party programs are installed into the system, this alignment will change. During its installation, third-party software often intercepts the role of default programs for supported file types. And such software, accordingly, arbitrarily makes settings in file associations - binding specific programs to specific types of files to open them by double-clicking. True, there are also such programs that, during their installation, offer the user to manually configure the file association - for example, select not all types of files, but only some. And even completely refuse to bind files to the program being installed.
Opening a movie in the window of a new media player or a link in a window of a new browser, arbitrarily and imperceptibly installed in the appendage of another, usually free program, is not the biggest problem. More precisely, not a problem at all, because this is a natural consequence of the last installed program intercepting its file types. Things will be much more difficult when, after unsuccessful experiments with Windows settings or as a result of malware penetration, system file associations fail. The failure of the associations of the executive.exe-files of programs and.lnk-files of shortcuts will make them impossible to start. So, instead of launching the desired program, we can get the launch of some other program. Or maybe it is: Windows will think that another program is needed to run one program. Naturally, the system will not find one, and it will have no choice but to offer a matching search on the Internet or in the Windows store. It will be no less problematic to encounter a failure of the .msi, .bat, .cpl system file associations, which will make it impossible to uninstall programs installed in the system, open folders or sections of the control panel, and other Windows functions.
Such problems are solved by changing the default programs and restoring the default file associations. All this will be discussed in detail below.
1. Setting default programs in File Explorer
You can return your favorite browser, text or graphics editor, media player, or other program so that they are associated with supported files in Windows Explorer. On the file of the desired type, right-click and select "Open with".
In Windows 7, in the window that appears, click the browse button.
And we specify the executable file by finding it on the C drive among the installed programs or in the storage location in the case of portable programs.
We check that the checkbox for using this program for all files of this type is checked. Click "OK".
In Windows 8.1 and 10, when you select the “Open with” command, we will see the same essence, but in a different design. If the proposed list of programs does not include the one you need, open the list by clicking "More applications" (or "Advanced").
Click the option to search for another application.
And in the explorer window, specify the path to the executable file. In order for the selected program to constantly open this type of file, check the box "Always use this application ...".
You can also assign a default program for a particular type of file in the properties of a separately selected file. Call the context menu on the file and click "Properties".
In the "Application" column, click "Edit".
And we indicate the desired program - a modern application, a program installed in the system or a portable program.
The context menu on files is the only way to set portable software as default programs. But for the programs installed in the system, there is also a toolkit as part of the Windows control panel.
2. Setting Default Programs in Control Panel
Let's go to the system control panel. Quick access to it is in the Windows 7 Start menu
and after pressing +X in Windows 8.1 and 10.
In all versions of Windows, the further path and functions will be the same. In the control panel window, select the "Programs" section.
And then in the "Default Programs" subsection, click "Set Default Programs".
We will see a list of programs installed in the system and modern / universal applications in the case of Windows 8.1 and 10. By selecting a program on the left in the right part of the window, you can set it as the default program. And this program will continue to open all supported files when you double-click on them.
Not all file types can be assigned to programs and applications in the list, but only some.
In the list of file types that opens, uncheck those that we do not want the program to play by default and click "Save".
By the same principle, you can configure the default openers for each individual file type. Returning to the window of the “Default Programs” subsection of the control panel, click on another item - “Assign a program to open files of this type”.
Now in the list we will see not programs, but, on the contrary, file types in alphabetical order. By selecting the desired format and clicking the "Change program" button, in this way, in fact, we will assign a program to this type of file that will open them by default.
In Windows 8.1 and 10, after the list of file types, there will be logs for launching applications, Chrome applications, individual mail functions or Skype functions, etc. Mapping these protocols to their applications is something that is not worth experimenting with for the sake of idle curiosity. After all, as a rule, these protocols are sharpened for specific functions of the system and programs.
3. Modern default program settings for Windows 8.1 and 10
You can set desktop programs and modern applications by default for each individual file type in Windows 8.1 both in the control panel and in the regular Settings application. The essence of these methods is the same, but the interface is different. Press the + Q keys and enter the query "default" in the search field. In the search results, select Default Application Settings.
In the modern program settings interface, by default, file types and protocols will be presented separately.
To set the default program for a particular file type, click the plus button or the icon of an existing program and specify the desired application or executable file of the desired program.
The same default program settings format is also present in Windows 10. But it is called, like the control panel section, “Default Programs”.
In addition to the ability to configure default programs, Windows 10 also provides the ability to reset file associations to the default ones, as they were immediately upon installation of the system.
4. Restoring default file associations
The methods discussed above will help in case of failure of document associations, media and other user files. However, if we are dealing with a failure of system files, in particular, the .exe and .lnk types mentioned above, here we need more serious intervention with editing the system registry. But we will not edit it manually, but we will take a simpler path and resort to importing ready-made .reg files - service files designed to make changes to the Windows registry. Provided specifically for restoring file associations to default settings, we will download .reg-files on the Internet.
4.1. For Windows 7
For Windows 7, such .reg files are posted on the Sevenforums.Com website. By clicking the "Download" button, you can download all available .reg files in one folder at a time.
And we can only upload individual ones.
The downloaded .reg file is launched by double clicking.
We confirm the launch.
We confirm the continuation of the process.
4.2. For Windows 8.1
By the same principle, we restore the default file associations in the Windows 8.1 system. We download from the site Eightforums.Com either individual .reg files, for example, to restore .exe or .lnk formats, or all .reg files in one folder.
Run the desired .reg file, confirm the action.
4.3. For Windows 10
.reg files that restore default file associations in Windows 10 can be downloaded from Tenforums.Com.
As in previous cases, run the desired .reg file, confirm the action.
5. File Association Fixer to restore default file associations
To restore default file associations, as an alternative to the previous method, you can use the free program File Association Fixer. This program works with Windows 7, 8.1 and 10 and will help you reset system file associations, in particular .exe and .lnk. We launch the program, go to the "Fix Files" tab, check the boxes for the desired file types and click "Fix Selected" at the bottom.
The File Association Fixer provides a way to launch itself even if the ".exe" file association fails. To run the program in this case, you must manually change the extension of the program's executable file from .exe to .com.
Have a great day!
File associations are called in the operating system the relationship between a file type and the application responsible for opening it.
So, for example, in the standard configuration of Windows 7, for opening a text file *.txt answers Notebook, for opening *.mp3 — Windows Media Player, per *.jpg — Fax and Picture Viewer, and so on…
But sometimes, for reasons of poor security, childhood, or just pranks, these ties are broken or lost. And the orgy begins. Music can open in Notepad, txt tries to "play" in the video player, etc.
Well if the problem is only with the files txt, mp3, or jpg. Then it is not difficult to fix the connection. But if the connection is broken *.exe files or shortcut links *.lnk, then chaos really begins on the computer.
As soon as the desktop background appears, all programs registered in startup try to start through some other programs. How else can you call it horror.
There are several solutions to this problem, all of them are different. Some we will consider briefly, some in more detail.
1. Restoring the previous state of the system
The easiest way to restore connections is to roll back the system to the moment when everything was working. This method is the most preferable, since there is no risk of making everything even worse than it is. But! This method will not work if the file association is broken *.exe - you will simply open something else instead of the recovery program. But if with connections exe and lnk it's ok - you can try the following:
Press the button to open the menu Start. Enter the command in the search bar:
rstrui.exe
The object you are looking for will appear in the result window. Run it as administrator as it shown on the picture:
The System Restore utility will launch. Click the button <Далее> .
In the list of restore points, select the date at which the file associations were in order. Don't forget to check the box as shown in the picture to see all the options. Click again <Далее>
.
File Association Violation is a nasty bug that causes programs and files to open incorrectly. Let's say all the applications on your computer run through Windows Media Center. This program is used only to play multimedia content, other files through it cannot be opened correctly by definition. To fix this error, you need to figure out how to restore file associations in Windows 7.
Bug fix
There are several ways to restore associations. Let's see them all so that if necessary, you can choose the appropriate method that will help solve the problem.
Important! Check the system for viruses before trying to fix the situation. Perhaps the reason for the change in the launcher lies in the penetration of malicious code into the system.
To open with
Recovery archive
- Locate and download the ResetFileAssociations.zip special registry repair archive.
Attention! This fix only works on Windows 7! For other versions of Windows, you need to use other archives, which can also be found on the Internet.
If you have a backup, you can restore the Windows 7 registry from it. For these purposes, you can also use the backup files automatically created by the system, stored in the Regback folder on the system drive.
You must have administrator rights to make changes to the registry.
Special software
Kaspersky Lab specialists have developed the CleanAutoRun utility, which helps to restore file associations after a virus attack. To fix errors with the launch of files and programs, open the CleanAutoRun utility and press any button. 
Another useful program is AVZ, designed to set up Windows 7 and restore a working configuration.
- Download the AVZ utility.
- Open the "File" menu and select "System Restore".
- Check "Restore file launch options" and click "Run".
Alternatively, you can use the FileAssociationFixer program. Here you need to select the desired extension in the categories on the left and start the process of restoring the correct configuration. 
Command line
Restart your computer and start in safe mode with command line support (press F8 at system startup and select the appropriate mode). 
Type the following commands, pressing the Enter key after each one:
assoc.exe = exefile
assoc.lnk=lnkfile
assoc.bat=batfile
If none of the above methods helped, try installing Windows 7 again. However, in 99% of cases, one of the described recovery options will suit you, so it almost never comes to reinstallation.
