I have Nokia Lumia 630 single sim phone. I have video file avseq.dat about 666 MB. I am unable to play this file in any way. Is there any solution? This file isn't shown in Microsoft video app. If you find a file with a.dat extension on your computer, it’s simply a generic data file that contains important information about the program used to create the particular file. It can be anything like an email attachment (as winmail.dat files), image or video, a document or even data, which stores information for software to handle. Thank you for visiting Microsoft Community. Generally these issues are fixed by changing the default applications that open the file or by performing system restore. You may use the specify the application that you want to use to open DAT files. Refer to the steps suggested under 'Choose default apps by file type or protocol' section. Windows file recovery license terms microsoft software license terms microsoft windows file recovery if you live in (or are a business with your principal place of business in) the united states, please read the “binding arbitration and class action waiver” section below.
-->A hive is a logical group of keys, subkeys, and values in the registry that has a set of supporting files loaded into memory when the operating system is started or a user logs in.
File Extension Dat Microsoft Visual C++
Each time a new user logs on to a computer, a new hive is created for that user with a separate file for the user profile. This is called the user profile hive. A user's hive contains specific registry information pertaining to the user's application settings, desktop, environment, network connections, and printers. User profile hives are located under the HKEY_USERS key.
Registry files have the following two formats: standard and latest. The standard format is the only format supported by Windows 2000. It is also supported by later versions of Windows for backward compatibility. The latest format is supported starting with Windows XP. On versions of Windows that support the latest format, the following hives still use the standard format: HKEY_CURRENT_USER, HKEY_LOCAL_MACHINESAM, HKEY_LOCAL_MACHINESecurity, and HKEY_USERS.DEFAULT; all other hives use the latest format.
Most of the supporting files for the hives are in the %SystemRoot%System32Config directory. These files are updated each time a user logs on. The file name extensions of the files in these directories, or in some cases a lack of an extension, indicate the type of data they contain. The following table lists these extensions along with a description of the data in the file.
| Extension | Description |
|---|---|
| none | A complete copy of the hive data. |
| .alt | A backup copy of the critical HKEY_LOCAL_MACHINESystem hive. Only the System key has an .alt file. |
| .log | A transaction log of changes to the keys and value entries in the hive. |
| .sav | A backup copy of a hive. Windows Server 2003 and Windows XP/2000: Copies of the hive files as they looked at the end of the text-mode stage in Setup. Setup has two stages: text mode and graphics mode. The hive is copied to a .sav file after the text-mode stage of setup to protect it from errors that might occur if the graphics-mode stage of setup fails. If setup fails during the graphics-mode stage, only the graphics-mode stage is repeated when the computer is restarted; the .sav file is used to restore the hive data. |
The following table lists the standard hives and their supporting files.
| Registry hive | Supporting files |
|---|---|
| HKEY_CURRENT_CONFIG | System, System.alt, System.log, System.sav |
| HKEY_CURRENT_USER | Ntuser.dat, Ntuser.dat.log |
| HKEY_LOCAL_MACHINESAM | Sam, Sam.log, Sam.sav |
| HKEY_LOCAL_MACHINESecurity | Security, Security.log, Security.sav |
| HKEY_LOCAL_MACHINESoftware | Software, Software.log, Software.sav |
| HKEY_LOCAL_MACHINESystem | System, System.alt, System.log, System.sav |
| HKEY_USERS.DEFAULT | Default, Default.log, Default.sav |
- 1.Data File
- 2.Piriform DAT File
- 3.Minecraft Data File
- 4.Piriform Key File
- 5.Inno Setup Uninstaller Data File
- 6.Windows Registry Hive File
- 7.Exchange E-mail Attachment
- 8.VCD Video File
- 9.Porteus Save Container File
- 10.Nonimmigrant Visa Application Data File
- 11.SimCity 4 Game Data File
- 12.GameMaker Studio Game Audio Data Package
File Type 1Data File
| Developer | N/A |
| Popularity | |
| Category | Data Files |
| Format | Text and Binary |
What is a DAT file?
A DAT file is a generic data file created by a specific application. It may contain data in binary or text format (text-based DAT files can be viewed in a text editor). DAT files are typically accessed only by the application that created them.
Many programs create, open, or reference DAT files. Additionally, many DAT files are only used for application support and are not meant to be opened manually by the user.
Open over 300 file formats with File Viewer Plus.Programs that open DAT files
File Type 2Piriform DAT File
| Developer | Piriform |
| Popularity | |
| Category | Misc Files |
| Format | N/A |
.DAT File Association 2
A DAT file is a data file used by Piriform applications, such as CCleaner, Speccy, Defraggler, and Recuva. It acts as a flag, telling a Piriform application to operate in portable mode, which is used when users want to run a Piriform application from a USB drive, or when users do not want to leave traces on a computer system.
To run a Piriform application in portable mode, create a blank file named piriform.dat and save it to the application's installation directory. For example, for CCleaner, the file can be saved to C:Program FilesCCleaner. After the file is saved, CCleaner will store program settings in a file named CCleaner.ini, rather than using other storage locations, such as the Windows registry.
NOTE: The contents of the piriform.dat file do not matter. Therefore, an empty file or a non-empty file that contains data will produce the same result.
portable.dat - The name of the DAT file used by the Piriform application to operate as the portable version.
Programs that open DAT files
File Type 3Minecraft Data File
| Developer | Mojang Specifications |
| Popularity | |
| Category | Game Files |
| Format | Binary |
.DAT File Association 3
A DAT file is a data file used by Minecraft, a 3D exploration and construction game. It is saved in a compressed Gzip format and may save various kinds of data, including player inventory, player position, and world information. DAT files are used for saving world state information as well as for tracking player progress.
DAT files were also used for storing level 'chunks,' which are small map pieces that are loaded on demand as a player navigates through the world. This format was introduced beginning with the Minecraft Infdev version, and the chunks used a 16 x 16 x 128 map dimension. Beginning with the Minecraft version 1.3 beta release, a new format called 'Region' was introduced, which stores chunks with the .MCR extension. Subsequently, the .MCA format, called 'Anvil,' was introduced with patch 1.2.1.
File Extension Dat Microsoft Office 2010
Minecraft DAT files have used different formats over incremental releases of the game. Therefore, one DAT file from one version of the game may not be compatible with another version.
NOTE: Minecraft is a first-person perspective game where players construct and destroy blocks and avoid monsters in a 3D environment. Minecraft server is a Java program that runs as a command-line interface.
level.dat - The Minecraft data file storing world information such as the player, the level generator used, and the time of day.
Programs that open DAT files
File Type 4Piriform Key File
| Developer | Piriform |
| Popularity | |
| Category | Data Files |
| Format | Text |
.DAT File Association 4
Key file used by Piriform applications, such as CCleaner and Recuva, that help users manage their PCs; contains the registry key number that is referenced by the application in order to operate in the appropriate mode.
NOTE: If the file is moved or deleted from its location in the application directory, the application will operate in the trial mode instead of the purchased mode.
Programs that open DAT files
File Type 5Inno Setup Uninstaller Data File
| Developer | Jordan Russel |
| Popularity | |
| Category | Misc Files |
| Format | Binary |
.DAT File Association 5
File created by Inno Setup, a program used for making Windows program installers and uninstallers; typically named unins000.dat (or a similar name) and is located in the program installation directory; contains data that helps Inno Setup uninstall the program when the user chooses to do so from the Windows Control Panel.
Inno Setup '.dat' file has a corresponding .EXE file named unins000.exe (or a similar name). When the executable is run, it uses the information in unins000.dat to uninstall the program from the Windows computer.
Programs that open DAT files
File Type 6Windows Registry Hive File
| Developer | Microsoft |
| Popularity | |
| Category | System Files |
| Format | Binary |
.DAT File Association 6
The Microsoft Windows registry uses DAT files to store user settings. Examples include passwords, account settings, and file associations. Certain DAT files are loaded when a user logs into Windows.
A common registry hive file is NTUSER.DAT, which stores user-level registry information. It is located in the following directory:
C:Users[user]
NOTE: NTUSER files contain important user settings and should not be deleted.
Another common DAT file is SCHEMA.DAT, which is a registry backup and restore file. It is located in:
C:WindowsSystem32SMIStoreMachine
NTUSER.DAT - stores Windows settings for a specific user
SCHEMA.DAT - Windows registry backup and restore file
Programs that open DAT files
File Type 7Exchange E-mail Attachment
| Developer | Microsoft |
| Popularity | |
| Category | Misc Files |
| Format | Binary |
.DAT File Association 7
Winmail.dat files contain formatting information for Rich Text (RTF) messages sent from Microsoft Exchange Server. They are added to the end of emails when a recipient's email client does not support RTF messages. The Winmail.dat file is not useful to users that do not use Outlook or Exchange Server to retrieve their mail.
Read more about Winmail.dat files, including how to open them and how to prevent them from being sent.
Winmail.dat - A file attached to the end of email messages when an email program cannot read the rich text formatting data from the source email. This file originates from a Microsoft Exchange Server.
Programs that open DAT files
File Type 8VCD Video File
| Developer | N/A |
| Popularity | |
| Category | Video Files |
| Format | Binary |
.DAT File Association 8
Video stream from a Video CD (VCD) disc; typically saved in MPEG-1 or MPEG-2 format; contains the actual video data that is played from the VCD.
NOTE: Video CD players should play the video from the DAT files without having to open the files manually.
Programs that open DAT files
File Type 9Porteus Save Container File
| Developer | Porteus Team |
| Popularity | |
| Category | Data Files |
| Format | N/A |
.DAT File Association 9
System save file used by Porteus, a portable Linux operating system (OS); contains saved changes that have been made to the Porteus OS; includes changes to system settings, bookmarks, downloaded files, and browser history.
The DAT file is used as a container that holds alterations you have made to Porteus, which enables you to keep your OS the same when installing it to other devices. It is a necessary container file if you are installing Porteus to devices formatted with a Windows file system. The file is used to retain data, such as symlinks, and Linux permissions, to run your system properly.
To create a DAT file container to save your customizations, boot Porteus into the KDE, Xfce, or LXDE desktop interfaces. After the boot is complete, open the menu and select System → Porteus save.dat manager. Then follow the prompts to finish creating your DAT file.
porteussave.dat - Common filename given when saving an OS session.
Programs that open DAT files
File Type 10Nonimmigrant Visa Application Data File
| Developer | U.S. Department of State |
| Popularity | |
| Category | Data Files |
| Format | Binary |
.DAT File Association 10
Application form data file created by the U.S. Online Nonimmigrant Visa Application (DS-160) process, which is made available from the U.S. Department of State's Consular Electronic Application Center; created by the online, browser-based application and contains data such as personal background information; used for saving and loading the application through the online form filing process.
Programs that open DAT files
File Type 11SimCity 4 Game Data File
| Developer | Electronic Arts |
| Popularity | |
| Category | Game Files |
| Format | Binary |
.DAT File Association 11
Game package file used by SimCity 4, a city building simulation game; may contain several types of game data files, including .SC4MODEL, .SC4LOT, and .SC4DESC files; used for packaging files into usable content for the game.
SimCity 4 DAT files can be browsed using iLives Reader or DatGen (developed by DarkMatter).
Programs that open DAT files
File Type 12GameMaker Studio Game Audio Data Package
| Developer | YoYo Games |
| Popularity | |
| Category | Game Files |
| Format | N/A |
.DAT File Association 12
A DAT file is a game data package created by GameMaker Studio, a cross-platform game engine. It contains a group of .WAV sound effect files that are featured in a game developed by GameMaker Studio. The DAT files are distributed with the game for which they contain audio assets.
GameMaker DAT files are created when a game developer chooses to save audio featured in a game in a package separate from the primary game asset package. The DAT files are not meant to be opened by a user. However, users that enjoy modifying gameplay can open DAT files with UndertaleModTool.
NOTE: Users should not modify games that they are legally restricted from modifying.
Programs that open DAT files