Automatically Backup the Registry daily using ERUNT

ERUNT is an excellent Registry Backup and Restore Utility for Windows NT/2000/2003/XP/Vista. This program backs up the DEFAULT, SAM, SECURITY, SOFTWARE, SYSTEM hives and also the per-user registry hives namely NTUSER.DAT & USRCLASS.DAT.

ERUNT works fine in Windows Vista if run under elevated privileges. To run the application elevated, right-click the file ERUNT.EXE which is located in "C:\Program Files\ERUNT" and choose Run as Administrator. Additional instructions are available in article Take a complete registry backup using ERUNT.

Note: Running ERUNT in a non-elevated mode would display the following error:

RegCreateKeyEx: 5 – Access is denied.

Create Automatic Registry Backups at Vista Startup

Using Task Scheduler, you can configure ERUNT to backup the registry at Startup (Note that ERUNT does not create a new backup if one already exists for the current day.) Follow these instructions:

1. Open Task Scheduler from Control Panel or by running the command control schedtasks from Start, Search box.

2. In the Actions pane on the right, click Create Task…

3. Type a name for the task that you want to create (for example, ERUNT), and optionally assign a descriptive text.

4. Click Change User or Group… button

5. Type SYSTEM and click OK

6. Enable the option Run with highest privileges. This is an important step.

7. Select the Triggers tab, and click New

8. In the Begin the task drop-down box, select At startup, and click OK

9. Select the Action tab, and click New

8. In the Program/script: text box, type the following (including the quotes):


9. In the Add arguments (optional) text box, type the following:

(Hint: Read ERUNT’s documentation to know the command line arguments supported.)

10. Click OK, OK.

You’ve now created a new task to backup the registry at every Startup. To verify if the task works, restart Windows and check the C:\Windows\ERDNT\AutoBackup folder.

About the author

Ramesh Srinivasan founded back in 2005. He is passionate about Microsoft technologies and has a vast experience in Windows — delivering support for Microsoft's consumer products. He has been a Microsoft MVP (2003-2012) who contributes to various Windows support forums.

7 thoughts on “Automatically Backup the Registry daily using ERUNT”

  1. Your instructions worked perfectly. However, I have since removed ERUNT from my system but the scheduled task still remains and I have no way of deleting it. The task shows up in the Task Scheduler Summary pane but not when I click on Task Scheduler Library, so there is no option to delete. Thanks.

  2. Thanks for taking the time to create this post, some of the simplest things are hard to figure out.

  3. I would also like to mention that if you read the readme and create a ERUNT.ini you are able to configure settings like default file location, file name format and so on.

  4. I prefer to use the date format 20131020 for directory names, as the alphanumerical sort order is the same as chronological.

    I use in ERUNT.INI:


  5. I prefer using regedit /e

    BAT file to backup entire registry + 7zip (went from 200MB+ to 6MB)


    @echo off

    set year=%date:~-4,4%
    set month=%date:~-10,2%
    set day=%date:~-7,2%
    set hour=%time:~-11,2%
    set hour=%hour: =0%
    set min=%time:~-8,2%

    set filename=X:\backup\registry.%year%.%month%.%day%.%hour%%min%

    regedit /e %filename%.reg”

    set AppExePath=”%ProgramFiles(x86)%\7-Zip\7z.exe”
    if not exist %AppExePath% set AppExePath=”%ProgramFiles%\7-Zip\7z.exe”

    if not exist %AppExePath% goto notInstalled

    %AppExePath% a -rt7z “%filename%.7z” %filename%.reg”

    del “%filename%.reg”

    goto end


    echo Can not find 7-Zip, please install it from:



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