Windows was created in a time when there were not a lot of users. Thus, Microsoft has not tweaked Windows in such a way that multiple users could use one computer. For this to happen, they had to provide personalization options to the user.

Now, you can do anything from happening separate profiles on the same computer to customization the Start Menu. The option to create different user profiles allows you to share a computer with someone without your work or user settings overlapping with theirs. In a way, you have two computers in one and Ntuser.dat is what makes this possible.

What is Ntuser.dat?

Ntuser.dat is present for every user profile. It is a registry file that contains the personalized settings for every user profile on the computer. Even if there is one profile, Ntuser.dat is present for it too. Therefore, it is very important for Windows since it is involved in the performance of different actions such as saving changes and loading files, etc. Whichever preference you set in your user profile, it is loaded again the next time you turn on the computer, thanks to Ntuser.dat.

Having separate user profiles is very beneficial in domestic and work settings. In an office setting, a single computer can have multiple user profiles so that the same computer can be used by different people working in different shifts. Similarly, at home, you can create different user profiles for yourself and your kids. In this way, their games do not overlap with your work, and your settings can be different from theirs. What allows this to happen? Ntuser.dat. It is responsible for

Why is Ntuser.dat Important?

When you are using your profile, you often make changes such as your display, resolution or printer, etc. For example, you might set a wallpaper of your pet on your screen. Now, the next time you turn on the computer, Windows should remember which wallpaper to show on the screen. Ntuser.dat helps in this.

Initially, Windows stores this information in the Registry. When you turn off the computer, this information is sent to Ntuser.dat. The next time you turn on the computer, this information will be loaded from Ntuser.dat and back to the Registry. Owing to this, you will be able to see the same settings as you had set before.

Ntuser.dat first came into being in the Windows 3.1 version. The ‘dat’ in the name represents that this extension contains data.

Back in the day, you could not make multiple user profiles. This is back when Windows was still in its earlier stages. Microsoft brought the option to create user profiles in Windows using the Ntuser.dat. This extension is present in every user profile.

How to Find the Ntuser.dat file?

As we have already mentioned, the Ntuser.dat file is present in every user profile. You can find it using one of the two ways.

Method 1: Run Window

To follow this method, press the Windows and R keys at once. When you see the Run window, type %userprofile% in the box and click OK.

  • Go to the ‘C’ folder and then to Users.
  • Click on your user name.
  • You will see the Ntuser.dat file there.
  • If you do not see this file, it means that it has been hidden by Microsoft so that you can edit or alter the file.
  • You can still see this file if you enable the Show Hidden Files option.

Method 2: File Explorer

  • For this method, click on My Computer or This PC icon present on your screen.
  • This will open File Explorer.
  • Click on the View tab and then click on the Hidden Items.
  • You will find Ntuser.dat here. Right-click on it to check its properties such as its size.

When you are looking for Ntuser.dat, you might see some other files named Ntuser.dat.LOG with a number in front. These are the backup files created by Microsoft. For example, when you save a new setting or preference such as a certain screen resolution for your user profile, Microsoft would make a copy of it and save it as Ntuser.dat.LOG and a number. So, these files that you see are important for your computer.

Is it safe to Delete Ntuser.dat?

Ntuser.dat takes up to 17 megabytes of space on your computer. This is not a lot of space as compared to some other programs but you might want to free up space. Do not delete Ntuser.dat even if you want to free up space on your desktop. Ntuser.dat is important for your user profile and if you delete it, you will only be making things uncomfortable for you.

Windows needs Ntuser.dat to load your saved settings and to ensure that you see things the way that you preferred them to be. If you have set a wallpaper, you would not want to set the desktop background every time you turn on the computer. You expect Windows to do this on its own. Windows cannot make this happen without Ntuser.dat.

Windows Cannot Sign In

If you delete the Ntuser.dat files, you will see a message on your screen that Windows cannot log in to your account. It will tell you that you can solve the problem by signing out of your user profile and then signing in again. However, even if you try this solution, you will not be able to sing in. Thus, it is best if you do not delete Ntuser.dat in the first place.

You will not be saving up a lot of space by deleting Ntuser.dat as it does take up a lot of space in the first place. If you want to delete a certain user profile, you can go ahead and do that.

Also, you should not alter this file. You might edit this file and cause more problems for your computer than you are able to fix. It is best to familiarize yourself with the important extensions and files so that you do not end up deleting them in an attempt to make some space on the desktop.


We hope that by now, you would have understood what Ntuser.dat does and why is it so important for your computer. If you have ever had the crazy idea of deleting this imperative data file from your computer, you should decide against it. Think of Ntuser.dat as a memory of user settings and preferences that Windows keeps. Without it, you would not be able to log in to your user profile as all your personalization will be gone. Let us know if you have any queries about this file.

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