.UB   Audio File or Raw Unsigned Byte (8-bit) Data

  .UC2  Compressed File

  .UDF  WindowsNT Uniqueness Database File

  .UDL  MS Data Link

  .UDW  Raw Unsigned DoubleWord (32-bit) Data

  .UI   User Interface

  .UL   uLAW Audio File

  .ULD  Procomm Uploaded Files

  .ULS  Internet Location Service

  .ULT  UltraTracker Module

  .UNI  MikMod (UniMod) Format

  .UNX  Text File (usually UNIX)

  .UPD  dBase Update File

  .UPO  dBase Compiled Update File

  .URL  Internet Location

  .USE  MKS Source Integrity File

  .USL  LaserJet Landscape Font

  .USP  PageMaker Printer Font or LaserJet Portrait Font

  .USR  User Database (various)

  .UTL  Sound File

  .UTP  BinPatch Patch Data File

  .UU   Compressed Archive File (UUENCODE)

  .UUD  Uudecoded

  .UUE  Uuencoded

  .UW   Audio File or Raw Unsigned Word (16-bit) Data

  .UWF  UltraTracker Wave File

  .V8   Covox 8-bit Audio

  .VAL  Validity Checks or dBase Values

  .VAP  Annotated Speech

  .VAR  Icon Author Variable

  .VBA  VBase File

  .VBG  Visual Basic Group Project

  .VBL  User Control Licensing File

  .VBP  Visual Basic Project

  .VBR  Remote Automation Registration Files

  .VBS  VBScript Script File

  .VBW  Visual Basic Project Workplace

  .VBX  Visual Basic Extension

  .VBZ  Wizard Launch File

  .VC   Spreadsheet File

  .VCE  Natural MicroSystems Voice File

  .VCF  vCard File or Vevi Configuration File

  .VCS  vCalendar File (Outlook)

  .VCT  FoxPro Class Library

  .VCX  FoxPro Class Library or Spreadsheet File

  .VDA  Targa Bitmap

  .VDO  VDOScript File

  .VEW  Clipper Viewfile

  .VGA  VGA Screen Driver or Targa Bitmap

  .VGR  Ventura Graphic

  .VI   Virtual Instrument LabView File

  .VIC  Picture File

  .VID  Monitor Control File or Screen Driver

  .VIK  Picture File

  .VIR  Virus Infected File (renamed by Symantec Anti-Virus)

  .VIS  Picture File

  .VIV  VivoActive Player Video File

  .VIZ  Division dVS/dVISE File

  .VLB  Corel Ventura Library

  .VMF  Ventura Font Characteristics or FaxWorks Audio File

  .VOC  Audio File or Creative Labs Sound

  .VOX  Vox Audio or Dialogic ADPCM or Talking Technology Inc. File or

        Natural MicroSystmes Voice File

  .VP   Ventura Publisher File

  .VQE  Yamaha Sound-VQ Locator File

  .VQF  Yamaha Sound-VQ File

  .VQL  Yamaha Sound-VQ Locator File

  .VRF  Oracle 7 Configuration File

  .VRS  WordPerfect Graphics Driver

  .VSD  Visio Drawing

  .VSL  GetRight Download List File

  .VSS  Visio Stencil

  .VST  Visio Template or Truevision Vista Graphic or Targa Bitmap

  .VSW  Visio Workspace File

  .VUE  dBase or Foxpro View

  .VVF  ViVerify Fingerprint

  .VVR  ViVerify Repair

  .VW   Volkswriter Text File

  .VWR  PC Tools File Viewer

  .VXD  Virtual Device Driver

  .W    Applause Word Chart

  .W30  Ventura Printer Font

  .W40  Win95 Backup File

  .WAB  Outlook File

  .WAD  Doom Game File

  .WAL  WalMaster Showlist File or Quake 2 Texture File

  .WAV  Waveform Audio (PCM Wave)

  .WB1  QuattroPro for Windows

  .WB2  QuattroPro for Windows

  .WBF  Windows Batch File

  .WBK  Word Backup or WP Workbook

  .WBL  Argo WebLoad II Upload File

  .WBR  Crick WordBar File

  .WBT  WinBatch Script or Crick Wordbar Template

  .WCD  WP Macro Token List

  .WCM  Works File Transmission or WordPerfect Macro

  .WDB  Works Database

  .WDK  WhizFolder Desktop File

  .WEB  Web Vector Graphic File or Corel Xara Web Document

  .WFB  Turtle Beach WaveFront Bank

  .WFD  Turtle Beach WaveFront Drum Set

  .WFN  Corel Symbols and Fonts

  .WFP  Turtle Beach WaveFront Program

  .WFX  Winfax Data File

  .WGP  Wild Board Games File

  .WHT  MS NetMeeting Old Whiteboard Document

  .WID  Ventura Width Table

  .WIF  Weaving Information Format or Image File

  .WIL  Windows Interface Language Script or WinImage File

  .WIN  dBase or Foxpro Window or Windows Backup File

  .WIZ  Wizard File

  .WK1  Lotus Spreadsheet File

  .WK3  Lotus Spreadsheet File

  .WK4  Lotus Spreadsheet File

  .WKB  WP Document

  .WKB  Workbook

  .WKE  Spreadsheet File

  .WKQ  Quattro Spreadsheet

  .WKS  Lotus Spreadsheet File or XLISP Workspace or Works Document

  .WKZ  Compressed Spreadsheet

  .WLD  REND386/AVRIL File

  .WLF  Argo WebLoad I Upload File

  .WLG  Dr. Watson Log

  .WLL  Word Add-in

  .WLR  VRML Page

  .WMA  Windows Media File

  .WMC  WP Macro or Wordmarc Text File

  .WMF  Windows Metafile

  .WN   Write Now Text File

  .WNF  Corel Outline Font

  .WOA  Windows Swap File

  .WOW  Grave Composer Music Module

  .WP   WordPerfect Document File

  .WP4  WordPerfect Document File

  .WP5  WordPerfect Document File

  .WP6  WordPerfect Document File

  .WPD  WordPerfect Screen Driver or Document

  .WPF  WordPerfect Text File or Enable Document

  .WPG  WordPerfect Graphics

  .WPK  Keyboard or WP Macros

  .WPM  WordPerfect Macro

  .WPS  Works Text Document

  .WPT  WordPerfect Template

  .WPW  PerfectWorks Document

  .WQ!  Compressed Spreadsheet

  .WQ1  Quattro Pro Spreadsheet

  .WQ2  Quattro Pro Spreadsheet

  .WR1  Symphony Spreadsheet File

  .WRD  Charisma Template

  .WR1  Symphony Document

  .WRI  Write Document

  .WRK  Spreadsheet File or Cakewalk Music Project File

  .WRL  Virtual Reality Model

  .WRP  Compressed Archive File

  .WRS  WP Windows Printer Driver

  .WRZ  VRML File

  .WS   WordStar Document

  .WS1  WordStar for Windows 1 Document

  .WS2  WordStar for Windows 2 Document

  .WS3  WordStar for Windows 3 Document

  .WS4  WordStar for Windows 4 Document

  .WS5  WordStar for Windows 5 Document

  .WS6  WordStar for Windows 6 Document

  .WS7  WordStar for Windows 7 Document

  .WSC  Windows Script Component

  .WSD  WordStar Data File

  .WSE  Wise File

  .WSH  Windows Script Host Settings File

  .WSQ  Wavelet-packet Scalar Quantization

  .WST  WordStar Text File

  .WVL  Wavelet Compressed Bitmap

  .WWL  Word Add-in File

  .WZN  WhizFolder Document

 .X    LEX Program File or AVS Image

  .X01  Paradox Secondary Index (can be 01 to 09)

  .X16  Macromedia Program Extension (16-bit)

  .X32  Macromedia Program Extension (32-bit)

  .XA   Extended Architecture File or File on PSX Disc

  .XAB  Xenis Mail Address Book

  .XAR  Corel Xara Drawing

  .XBM  X Bitmap Graphic

  .XFN  Ventura Printer Font

  .XFT  Chiwriter 24 Pin Printer Font

  .XFX  Fax File (various)

  .XI   Fast Tracker 2 Instrument or ScreamTracker Instrument File

  .XIF  Wang Image File or Xerox Image File

  .XLA  Excel Add-in

  .XLB  Excel File

  .XLC  Excel Chart

  .XLD  Excel Dialog

  .XLG  Xnetech Engraving Logo File

  .XLK  Excel Backup

  .XLL  Excel Add-in (Dynamic Link Library)

  .XLM  Excel Macro

  .XLS  Excel Worksheet

  .XLT  Excel Template or Lotus Translation Table

  .XLV  Excel VBA

  .XLW  Excel Workspace

  .XM   Sound File or Fast Tracker 2 Extended Module

  .XML  Expanded HTML File

  .XNK  Exchange Shortcut

  .XOT  Xnetech Job Output File

  .XPM  X Picsmap Graphic

  .XQT  SuperCalc Macro Sheet

  .XRF  Cross Reference

  .XR1  Epic MegaGames Xargon File

  .XSL  XML Stylesheet

  .XT*  Crosstalk Related File

  .XWD  X Windows Dump or Crossdown Puzzle File

  .XWF  Yamaha XG Works File

  .XXE  Xxencoded File

  .XY   XYWrite Text File

  .XY3  XYWrite Text File

  .XY4  XYWrite IV Document

  .XYP  XYWrite III Plus Document

  .XYW  XYWrite Windows 4.0 Document

  .Y    Compressed Archive File

  .Y01  Paradox Secondary Index (can be 01 to 09)

  .YAL  Arts & Letters Clipart

  .YBK  Encarta Yearbook

  .YUV  Color Space Pixel Format

  .Z    Compressed Archive File

  .ZC   Zipkey File

  .ZIP  Compressed Archive File

  .ZOM  Compressed Archive File

  .ZOO  Compressed Archive File

  .ZVD  ZyXEL Voice File

  .ZW   Chinese

  .~    Temporary File

  .~MN  Norton Menu Backup