.IDL File Recovery

Have files been deleted due to a user’s error or software error? Have you formatted a disk by accident and need to know how to recover the files? Read our .IDL file recovery guide for Windows, MacOS, Android and IOS in 2024.

IDL File Recovery

What is a .IDL file?

Source code file created using the Microsoft Interface Definition Language (MIDL); contains interface and type library definitions; used for defining interfaces between client and server applications; also used for generating type libraries (.TLB files) for OLE automation.

What Are Common Causes of ".IDL" Files Lost or Failure?

There are several common causes of ".IDL" files being lost or experiencing failure:

  1. Accidental deletion: Users may accidentally delete ".IDL" files while cleaning up their system or organizing files, leading to their loss.
  2. Software or hardware issues: Software or hardware malfunctions, such as system crashes, power outages, or disk failures, can result in the corruption or loss of ".IDL" files.
  3. Virus or malware attacks: Viruses or malware can infect and damage ".IDL" files, making them inaccessible or causing them to be deleted.
  4. Improper shutdown: If a computer is improperly shut down, such as through a sudden power loss or manual restart, it can cause ".IDL" files to become corrupted or lost.
  5. File system errors: File system errors, such as disk fragmentation or errors in the file allocation table, can lead to the loss or corruption of ".IDL" files.
  6. Human error: Mistakes made by users, such as accidental formatting of a storage device or overwriting ".IDL" files with incorrect data, can result in their loss or failure.
  7. Software conflicts or incompatibility: Incompatibility issues between different software applications or conflicts with system updates can cause ".IDL" files to become inaccessible or fail to function properly.
  8. Network issues: If ".IDL" files are stored on a network drive or accessed over a network connection, issues like network failures or interruptions can lead to their loss or failure.

It is important to regularly backup ".IDL" files and take preventive measures, such as using reliable antivirus software and practicing safe computing habits, to minimize the risk of losing or experiencing failure with these files.

How to recover lost ".IDL" files?

Sometimes while working with a computer, laptop or other stationary or mobile devices, you may encounter various bugs, freezes, hardware or software failures, even in spite of regular updates and junk cleaning. As a result, an important ".IDL" file may be deleted.

Go to view
🧺 How to Recover Files and Folders After Sending Them to the Recycle Bin and Deleting? (Windows 11)

🧺 How to Recover Files and Folders After Sending Them to the Recycle Bin and Deleting? (Windows 11)

By no means should you think that the only way to recover a ".IDL" file is always to create it once more.

Use programs for recovering ".IDL" files if a file was lost after accidental or deliberate deleting, formatting the memory card or the internal storage, cleaning the storage device, after a virus attack or a system failure.

Programs to recover ".IDL" files

Looking for a way to get files back? In cases when files were deleted and they cannot be restored by using standard operating system tools, use Hetman Partition Recovery.

The tool recovers data from any devices, regardless of the cause of data loss.

Follow the directions below:

  1. Download Hetman Partition Recovery, install and start the program.

  2. The program will automatically scan the computer and display all hard disks and removable drives connected to it, as well as physical and local disks.

    File Recovery Software
  3. Double-click on the disk from which you need to recover ".IDL" files, and select analysis type.

    Hetman Partition Recovery - Analysis Type
  4. When the scanning is over, you will be shown the files for recovery.

    Hetman Partition Recovery - Files that Can be Restored
  5. To find a file you need, use the program’s interface to open the folder it was deleted from, or go to the folder "Content-Aware Analysis" and select the required file type.

    Hetman Partition Recovery - Deep Scan
  6. Select the files you have been looking for and click "Recovery".

    File Recovery Software - Files List for Recovery
  7. Choose one of the methods for saving the files and recover them.

    Saving recovered files in Hetman Partition Recovery

How to open file with ".IDL" extension?

Looking for how to open a stereo interface Definition Language File image file file?

Programs that open ".IDL" files

Microsoft Visual Studio 2019 Microsoft Visual Studio 2019

Additional Information

  • File type: Interface Definition Language File

  • File extension: .IDL

  • Developer: Microsoft

  • Category: Developer Files

  • Format: N/A


We will be happy to answer your questions!

Comments (1)

  • Hetman Software: Data Recovery
    Hetman Software: Data Recovery 18.12.2019 15:23 #
    Leave a comment if you have any questions about Recovering lost .IDL files after deleting, cleaning or formatting!
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Vladimir Artiukh

Author: Vladimir Artiukh, Technical Writer

Vladimir Artiukh is a technical writer for Hetman Software, as well as the voice and face of their English-speaking YouTube channel, Hetman Software: Data Recovery for Windows. He handles tutorials, how-tos, and detailed reviews on how the company’s tools work with all kinds of data storage devices.

Oleg Afonin

Editor: Oleg Afonin, Technical Writer

Oleg Afonin is an expert in mobile forensics, data recovery and computer systems. He often attends large data security conferences, and writes several blogs for such resources as xaker.ru, Elcomsoft and Habr. In addition to his online activities, Oleg’s articles are also published in professional magazines. Also, Oleg Afonin is the co-author of a well-known book, Mobile Forensics - Advanced Investigative Strategies.


Questions and answers

  • What is an .IDL format and how is it used in software development?

    IDL stands for Interface Definition Language. It is a language-independent format used to describe the interfaces of software components in a distributed system.

    In software development, IDL is used to define the interface between different software components or modules, enabling them to communicate with each other. It provides a standard way to describe the methods, parameters, and data types that can be used to interact with a particular component.

    IDL files are typically written in a syntax that is independent of any specific programming language, allowing developers to define interfaces in a language-neutral manner. These IDL files are then used to generate code stubs or skeletons in various programming languages, which can be implemented by the respective components.

    Using IDL in software development offers several benefits. It promotes interoperability, as components written in different languages can communicate using a common interface. It also enables separation of concerns, allowing developers to focus on implementing the functionality of a component without worrying about the details of communication protocols. Additionally, IDL facilitates the development of distributed systems by providing a clear specification of the interfaces, making it easier to integrate and maintain different components.

  • What are the advantages of using .IDL formats in inter-process communication?

    There are several advantages of using .IDL (Interface Definition Language) formats in inter-process communication:

    1. Language and platform independence: .IDL provides a standardized way to define interfaces between different processes, irrespective of the programming language or platform they are implemented in. This allows for interoperability and seamless communication between processes written in different languages.
    2. Interface contract enforcement: .IDL helps in enforcing a strict contract between the communicating processes. By defining the interface in a separate .IDL file, both the client and server processes can ensure that they adhere to the specified interface methods, parameters, and data types. This helps in avoiding compatibility issues and ensures that the communication is well-defined and reliable.
    3. Automatic code generation: .IDL files can be used to automatically generate code stubs or proxies in different programming languages. These generated code files can handle the low-level details of communication, such as marshaling and unmarshaling data, making it easier for developers to focus on the actual logic of their processes. This saves development time and reduces the chances of errors.
    4. Versioning and evolution: As systems evolve and interfaces change, using .IDL formats allows for easier versioning and evolution of the communication protocol. By maintaining backward compatibility and providing mechanisms for handling different versions of the interface, processes can be updated independently without breaking the communication between them.
    5. Documentation and clarity: .IDL files serve as a documentation of the interface, making it easier for developers to understand and implement the communication protocol. By having a clear and well-defined interface description, developers can ensure that the communication is done correctly, reducing the chances of misunderstandings or misinterpretations.

    Overall, using .IDL formats in inter-process communication provides a standardized, language-independent, and efficient way to define, enforce, and document the communication interface, leading to improved interoperability and ease of development.

  • Can you provide an example of a popular .IDL format used in a specific programming language or technology?

    One popular .IDL format used in the COM (Component Object Model) technology is the Microsoft Interface Definition Language (MIDL). MIDL is used to define the interfaces, data structures, and constants that are used in COM components. Here's an example of a simple .idl file:


    import "oaidl.idl";

    import "ocidl.idl";

    // Define a simple interface





    helpstring("ISampleInterface Interface"),



    interface ISampleInterface : IDispatch {

    HRESULT SampleMethod([in] BSTR inputString, [out, retval] BSTR* outputString);


    // Define a coclass implementing the interface



    helpstring("SampleClass Class")


    coclass SampleClass {

    [default] interface ISampleInterface;



    In this example, the .idl file defines an interface called `ISampleInterface` that inherits from the `IDispatch` interface. It also defines a coclass called `SampleClass` that implements the `ISampleInterface`. The interfaces and coclasses defined in the .idl file can be used to generate code stubs and type libraries for use in COM development.

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