NU3 file format description

Many people often share .nu3 files without providing instructions on how to use them. This can make it difficult for users to determine which program is compatible for editing, converting, or printing .nu3 files. To address this issue, we have created this page to offer assistance and guidance on handling .nu3 files. We provide information on compatible software, editing instructions and conversion options to help users effectively interact with .nu3 files.

Our aim is to simplify the process and promote seamless use of the .nu3 file format.

1 filename extension(s) found in our database.

.nu3 - Norton Utilities Backup Data

The NU3 data files are related to Norton Utilities. The NU3 file is a Norton Utilities Backup Data. Norton Utilities is a utility software suite designed to help analyze, configure, optimize and maintain a computer.

Application:Norton Utilities
Category:Data files
Magic:- / -

Norton Utilities Backup Data related extensions:

  • t16 H&R Block 2016 Tax Return Data
  • hmhd Microsoft Word for Mac Hyphenation Data
  • schd Microsoft Excel Schedule Data
  • obr Objective ECM Reference Document Link
  • s12 WISO Steuer-Sparbuch 2012 Data
  • spdb Sticky Password Sync Database

Be careful.

It is important to understand that the .nu3 file extension is not limited to a particular set of applications. Other programs besides the intended ones can also use the .nu3 extension to create files. This includes potentially harmful programs or malware that may generate .nu3 files for various purposes. Be especially cautious with .nu3 files coming from untrusted or unknown sources.

Can't open a .nu3 file?

When you double-click a file to open it, Windows examines the filename extension. If Windows recognizes the filename extension, it opens the file in the program that is associated with that filename extension. When Windows does not recognize an extension, you receive the following message:

Select an app to open this .nu3 file

To set the .nu3 file association in Windows 11, you can follow these steps

  1. Open the Settings app by clicking on the Start menu and selecting the gear icon.
  2. In the Settings app, click on System and then select Apps from the left-hand side menu.
  3. Scroll down and click on the Default apps option.
  4. Under the Default apps section, you will find various categories such as Email, Web browser, and Music player.
  5. Locate the category that matches the file type you want to associate, such as Photos for image files or Video player for video files.
  6. Click on the current default app listed under the category. A list of available apps will appear.
  7. Choose the app you want to set as the default for that file type. If the desired app is not listed, click on More apps to see additional options or click on Look for an app in the Microsoft Store to search for apps in the Store.
  8. After selecting the app, it will become the default choice for opening files of that type.

It's worth mentioning that you don't always need to set .nu3 file association. Many applications can open .nu3 files without requiring any specific file association to be set.

The .nu3 file extension is often given incorrectly

Based on searches conducted on our site in the past year, we have compiled a list of the most common misspellings. These frequent misspellings can cause confusion and hinder search accuracy. Our goal in providing this list is to help users find the right information more easily and enhance their overall search experience on our website.

These misspellings were the most common in the past year:

mu3, n3, un3

Is it possible that the filename extension is misspelled?

There is a possibility that the .nu3 filename extension is misspelled. To assist users in identifying potential errors, we provide a list of similar file extensions in our database.

Filename extensions similar to .nu3:

Operating systems

At, we strive to provide a seamless user experience by ensuring compatibility with a wide range of operating systems. The following is a comprehensive list of the operating systems currently supported by

Windows XP/Vista, Windows 7/8/10, Windows 11, CentOS, Debian GNU/Linux, Ubuntu Linux, FreeBSD, macOS, Mac OS X, iOS, Android

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If you find the information on this .nu3 page useful, please feel free to link to this page. >> NU3 file