File formats starting with a letter U

File formats starting with a letter U

.u Subsampled Raw YUV Bitmap Image
.u00 The Price Is Right 2010 Game
.u01 Barudan Embroidery
.u08 UFile Data
.u10 UFile 2010 Tax Return Format
.u11 UFile 2011 Tax Return Format
.u12 UFile 2012 Tax Return Format
.u255law Exponential 8-bit Sound
.u2car NFS:U2 Car
.u32 Authorware Cover
.u3d Universal 3D Format
.u3i U3 Application Information Format
.u3p U3 Platform Install Format
.u8 Lemings 3D Audio Format
.u96 EasyZip Temporary
.uae WinUAE Configuration
.ual Entrust Unattended Login Credentials
.uap SIMATIC WinCC User Archive Export
.uaq Microsoft Windows Action Queue
.uas Ulead PhotoImpact Backup
.uav OpenPilot UAV Settings
.uax Unreal Audio Format
.ub Unsigned Byte Audio Format
.ubifs Linux UBIFS Image
.ubj Universal Binary JSON Fiile
.ubm IPhoto Mtwain Install
.ubox Universe Sandbox Saved Data Format
.ubr IIS WCAT Configuration
.uc UnrealScript Class
.uc2 UltraCompressor II Compressed Archive Format
.uccapilog Microsoft Windows Live Messenger UCC API Log Format
.ucd Prosa Diagram
.uce Microsoft Windows XP System32 Format
.ucf WebEx Universal Communications Format
.uci UFS Explorer Backup Format
.ucl Unreal Tournament Cache Format
.ucls ObjectAid UML Explorer Class Diagram
.ucm Urban Chaos Game Format
.ucp SmartWare Communications Profile
.ucr MicroSim PCBoard Unrouted Nets Report
.ucs Homeworld Localized Unicode Strings
.ucsettings Universal Converter Settings
.uct UC Browser Theme Format
.ucv Universal Converter Conversion
.ucx Rational XDE
.ud OmniPage User Dictionary
.uda ZEMAX Model Data
.udb Dynamics AX User Database Format
.udc Adobe User Dictionary Format
.udcx Microsoft Office Universal Data Connection Format
.udeb Debian Package Format
.udf Universal Disk Format
.udg UDraw(Graph)
.udi CorelDRAW Draw Script Textures Bitmap
.udid Google Android Unique Device IDentifier
.udif Apple Mac OS X Universal Disk Image Format
.udk Unreal Map Format
.udl Microsoft Data Link Format
.udm MapView User Module
.udo Moray UDO 3D
.udp Corel VideoStudio Scene Information
.uds FIMware Database Format
.udw Raw Unsigned DoubleWord (32-bit) Data
.udx PI Expert Design Software
.uea Protector Suite QL Format
.ueed Uconomix Encryption Engine Encrypted Directory
.uenc UltraEdit Encrypted Text
.ues Ulead Photo Explorer Slide Show
.uew UltraEdit Wordfile
.uez Ulead COOL 3D Graphics
.ufa GIF Animator Animation Object Information
.ufc SATURN Suite
.ufdr UFED Physical Analyzer Report Package
.uff DataWave SciWorks Physiological Data
.ufi UFOCaptureV2
.ufo Ulead PhotoImpact Object Format
.ufp Ulead Photo Project
.ufr Ultra Fractal Format
.ufs FreeBSD PC-BSD Unix File System Format
.ufs.uzip FreeBSD Compressed Unix File System Format
.ufx Ultimate 3D Game Engine Material
.ugd Need For Speed Underground
.ugr Apophysis Gradient
.uha UHARC Compressed Archive
.uhh Eurotherm Hydra History Encrypted
.uhs Universal Hint System Binary
.uhtm Unreal Tournament
.uhtml UHTML Document Format
.ui User Interface Format
.uibak UltraISO Backup Disk Image
.uic COCO Unit ICon
.uid IBM Voice Type Users
.uid-zps Zoner Photo Studio Picture Autobackup
.uif MagicISO Universal Image Format
.uil IBM AIX User Interface Language
.uin ICQ 2001 Saved ICQ Contact Information
.uir LabWindows User Interface Resource
.uis WindowBlinds Personality Format
.uit UIX XML Template
.uix UiXML Page
.uiz Spybot Search & Destroy Updater
.uk English (British) Language Translation
.uka Fifa World Cup Game Data
.uks Microsoft Works
.ukx Unreal Tournament Animation Format
.uky UltraMixer Licence Key
.ulaw Raw CCITT/ITU G.711 US Telephony Audio Format
.ulb COBOL Unisys Library
.uld Unified Luminaire Datafile
.ulf Universal List Format
.ulp EAGLE Script
.uls NetMeeting User Location Service Format
.ult Ultratracker Music Module (MOD) Format
.ulw U-Law Audio Format
.ulys Ulysses Project
.ulz USBlyzer Data Capture Format
.umb MemMaker Backup
.umd UMD Mobile Ebook
.umf MediaHolder Media Format
.uml Visual UML Class Diagram & Model Format
.umlclass Java UML Class Model Format
.umlx Visual UML XML Model
.umm Unified Molecular Modeling
.umod Unreal Tournament MOD Installation Package Format
.ump UModel Project
.umr MyEclipse UML Model Repository
.ums Rune 3D Mesh Format
.umx Deus Ex Format
.una SIMS Unauthorized Data
.unauth SiteMinder Unauthorized Message Format
.uncompressed_size Singularity Game
.unf Btreive Unformatted
.uni UniMOD/MikMOD Music Module Format
.unitxt YS FLIGHT Language
.unity Unity Scene Format
.unity3d Unity Scene Web Player Format
.unitypackage Unity Package Format
.unityproj Unity 3D Project
.unit_variant Total War Unit Variant Settings
.unix Unix
.unk UVProbe Format
.unknown Unknown File Extension
.unl Garmin MapSource Unlock Format
.unq ACT! 3.0 Email Message Attachment
.unr Unreal Map Format
.uns Visual Navigation Suite Export Or Import Settings
.unt AutoCAD Unit Definition Format
.unused Photoline 4 Defaults
.unv BusinessObjects Universe
.unx Unix Text Format
.uof Uniform Office Format
.uol PhotoImpact Clipart Image
.uop Unified Office Format Presentation Format
.uos Unified Office Format Spreadsheet Format
.uot Unified Office Format Text Format
.upc Ultimate Paint Component
.upd Update Format
.update ISAPI Update Format
.updatr IConomy Update Format
.updf UltraPdf Publication
.upf Nokia Phone Digital Photo Format
.upg Firmware Upgrade Format
.upi Ulead PhotoImpact Plugin
.upj Ulead Project
.upk Unreal 3 Game Data Package Format
.upk0 Metro 2033 Game
.upl StarMoney Agent Download
.upm PenMail
.upo DBASE Compiled Update Data
.upoi IGO Points Of Interest Format
.upp Ghostscript Uniprint Unified Printer Parameter
.upr FileMaker User Spelling Dictionary
.ups Microsoft Works
.upx Ultimate Packer For EXecutable Format
.upz StarMoney Agent Download
.uqm The Ur-Quan Masters Archive Format
.urc Unicenter Remote Control
.urd Ultra Recall Database
.urd-journal Ultra Recall Journal Update
.urf AppFace Skin
.url Internet Shortcut - URL - Uniform Resource Locator
.urls GetRight Internet Shortcuts List
.url_ Internet Shortcut - URL - Uniform Resource Locator
.urp Universal Report
.urq Review QuickChart Chart
.urr Uniface Signatures Format
.urs ControlDraw User Requirement Specifier
.urt Utah Run-Length Encoded Bitmap Image Format
.us English Language Translation
.us? Microsoft Word Font
.usa Microsoft Office Headers Format
.usb SiSoftware Sandra
.usc USC Module Definition
.usecasediagram Microsoft Visual Studio Use Case Diagram
.useq USeq Genome Data Format
.user Microsoft Visual Studio Project User Options Format
.userprofile Norton Antivirus User Profile Format
.usertile-ms Microsoft Windows 8 Release Preview User Tile Format
.usf Nintendo Ultra 64 Sound Format
.usflib Nintendo 64 Song Library Format
.usg PC-Doctor For Windows
.ush Creston SIMPL Windows
.usi UsiXML UI Description
.usl ProWORX Nxt USL Loadable
.usm USM Game Video Format
.usp PageMaker Printer Font
.usr FileMaker Pro Runtime Engine Database Application
.uss WinUAE Saved State
.ust WiFi SiStr Exported User Theme Format
.ustar Uniform Standard Tape Archive Format
.usx Unreal StaticMesh (hardware Brushes) Format
.ut2 Unreal Tournament Map Format
.ut2mod Unreal Tournament 2003 MOD Installation Package Format
.ut3 Unreal Tournament 3 Map Format
.ut4mod Unreal Tournament 2004 MOD Installation Package Format
.ut8 Ghost Master Language Format
.utb µTBackup Backup
.utc BioWare Aurora Game Engine Creature Format
.utd BioWare Aurora Game Engine Door
.ute BioWare Aurora Game Engine Encounter
.utf8 Unicode UTF-8 Encoded Text
.uti Spybot - Search & Destroy Includes
.utl QuickBooks Data
.utm BioWare Aurora Game Engine Store
.utp BioWare Aurora Game Engine Placeable Object
.utpart µTorrent Unfinished Download
.uts Spybot - Search & Destroy Include
.utt BioWare Aurora Engine Trigger
.utw Unity Whirld Format
.utx Unreal Texture Format
.utxt Unicode Text Format
.utz UIQ Theme Package
.uu Uuencoded (compressed) File Archive (ascii)
.uud UUDecoded Format
.uue UUEncoded Format
.uus Ultra Utility Skin
.uv2 µVision Project
.uvcab UVScreenCamera Films
.uvf Uncertain Value Format
.uvnts UVScreenCamera Notes
.uvproj µVision4 Project
.uvr UVR Mesh
.uvs UVScreenCamera Segments
.uvseg UVScreenCamera Segments
.uvw 3D Studio MAX UVW Coordinates
.uvx Unreal Tournament Saved Game
.uw Unsigned Word (16-bit) Music Format
.uwf UltraTracker WaveSample Music Format
.uwl Corel WordPerfect User Word List Format
.uxdc Microsoft Excel Data Retrieval Service Connection
.uxf UMLet UML EXchange Format
.uxx Unreal Tournament 2003 Cache Format
.uxy Barudan Embroidery Outline
.uyvy YUV 16-bit Image Format
.uz2 Unreal Tournament Compressed
.uze UltimateZip Compressed Archive
.uzip FreeBSD Compressed Disk Image Format
.uzy Backdoor.Sokacaps
I cannot see the file extensions. What should I do?

File extensions are not normally displayed to users. To change this, go to Control Panel, select Appearance and Personalization and Folder Options. Next, select the View and find the option "Hide extensions for known file types". The option should be deselected (cleared) and confirmed with OK.