Can’t Open BAK Files: How to Fix It

If you’ve ever encountered a BAK file while working in AutoCAD, you might wonder how to open it or why it exists. BAK files can be confusing when you don’t know their purpose or how to use them. In this article, we’ll explain what BAK files are and provide a detailed, step-by-step guide on how to open them in AutoCAD, as well as address common issues you might face.

What Are BAK Files in AutoCAD?

A BAK file is an automatically created backup file generated by AutoCAD. Whenever you save a drawing, AutoCAD creates a BAK file of the previous version. This is a safeguard that helps protect your work in case something goes wrong with the original file, such as corruption or accidental deletion. BAK files are typically located in the same folder as the DWG file and have the same name but with a .bak extension.

Why Can’t You Open BAK Files Directly?

Unlike DWG files, BAK files can’t be opened directly in AutoCAD because they are backup files designed to restore data in case of an issue. However, they contain the same drawing information as DWG files and can easily be converted into a DWG format that AutoCAD recognizes. The reason they are not openable directly is to prevent confusion and accidental modifications.

Note: BAK files are crucial for safeguarding your work, and having them ensures you can recover an earlier version of your drawing in case of corruption or unintended changes.

How to Open BAK Files in AutoCAD (Step-by-Step Guide)

Here’s how you can open BAK files and recover your drawing:

1. Locate the BAK File

• Go to the folder where your AutoCAD drawings are saved.
• Look for the BAK file that corresponds to the drawing you want to recover. It will have the same name as your original drawing but with a .bak extension.
  

  Tip: If you have many files in the folder and can’t find the BAK file easily, use the search function of your file explorer. In Windows, click on the search bar and type *.bak to list all backup files in the folder.

2. Show File Extensions (if necessary)

• If you don’t see file extensions (such as .bak) in the file names, you need to enable this setting. In Windows, go to the View tab in the file explorer and check the box labeled File name extensions. This will display the file types, allowing you to identify the BAK file more easily.

3. Change the File Extension

• Right-click on the BAK file and select Rename.
• Change the file extension from .bak to .dwg. For example, if your file is named project.bak, rename it to project.dwg.
• Press Enter to confirm the changes.
  

  Note: Renaming the file doesn’t alter its contents—it simply changes how the system and AutoCAD recognize the file. By renaming the file to .dwg, AutoCAD will now treat it as a regular drawing file.

4. Open the File in AutoCAD

• Once you have renamed the file, you can now open it in AutoCAD.
• Launch AutoCAD, go to File > Open, and browse for the renamed file. Select it and click Open.

5. Save Your Recovered File

• After successfully opening the file, save it under a new name to avoid any potential confusion.
• Go to File > Save As, and give your file a new name. This ensures your original DWG file is untouched, and you have a backup of the version you recovered.

What to Do If Renaming the File Doesn’t Work

In some cases, even after renaming a BAK file to .dwg, AutoCAD might still fail to open it. Here are some common reasons why this happens and how to fix them:

1. File Corruption

• If the BAK file itself is corrupted, AutoCAD will not be able to open it even after changing the extension.
• Solution: Try using AutoCAD’s built-in Recover tool. Go to File > Drawing Utilities > Recover, then select the renamed DWG file. AutoCAD will attempt to repair the file and open it.
• If this doesn’t work, consider using third-party software designed to repair corrupted DWG files.

2. File Permissions

• Sometimes, the file may be set to read-only or you may not have the correct permissions to open it.
• Solution: Right-click the file, select Properties, and check if the Read-Only attribute is selected. If so, uncheck it and apply the changes. Also, ensure you have the proper file permissions (especially if you’re working on a network or shared drive).

3. Compatibility Issues

• The BAK file may have been created in a version of AutoCAD that is newer than the one you’re using.
• Solution: Make sure you are using a compatible version of AutoCAD that supports the file. If you don’t have the latest version, try opening the file on a system with a newer AutoCAD version and saving it in a compatible format.

4. Temporary System or AutoCAD Errors

• Occasionally, temporary system errors or software bugs can prevent the file from opening.
• Solution: Restart AutoCAD or your computer, then try opening the file again. Ensure that your AutoCAD installation is updated to the latest version as some bugs or issues may be resolved in newer updates.

Tips for Preventing Data Loss

1. Set Auto Save Intervals
   Make sure that AutoCAD’s auto-save feature is turned on and set to save your work at regular intervals. You can adjust this in the Options menu under the Open and Save tab. This reduces the risk of losing significant progress in case of a crash.
2. Keep Multiple Backups
   Regularly create manual backups of your important drawings. You can store these backups on external hard drives or cloud storage solutions like Google Drive or Dropbox for additional protection.
3. Use a File Versioning System
   Employ a file versioning system or drawing management software that tracks changes and maintains a complete version history of your drawings. This allows you to revert to an older version at any time without needing to rely solely on BAK files.

Conclusion

BAK files in AutoCAD serve as an essential safety net for protecting your work. While they can’t be opened directly in AutoCAD, you can easily recover drawings by renaming the file extension to .dwg. If renaming doesn’t work, it’s important to consider file corruption, permissions, compatibility, or system errors and follow the outlined troubleshooting steps.

By following these simple steps and preventive measures, you can minimize data loss and ensure that your work is always safe. If you have any questions or run into further issues, don’t hesitate to seek support from the AutoCAD community or professionals.