| wa_ | Compressed WAV File |
| wb4 | WindowBlinds 4 Default Skin |
| wba | WindowBlinds Skin |
| wbb | WinBackup Archive |
| wbc | Webshots Image Collection |
| wbcat | Windows Backup Catalog |
| wbd | Softlink Whiteboard |
| wbd | eBeam Whiteboard |
| wbdp | ANSYS Workbench DesignPoint Data |
| wbex | ANSYS Workbench Extension |
| wbf | TusiSoft Polyglot Dictionary Data |
| wbl | OPM WAP Bookmarks Archive |
| wbl | Homemeeting Messenger Web Office Server List File |
| wbr | WriteOnline Wordbar Data |
| wbv | WordBanks Editor Data |
| wbverify | Windows Backup Verify File |
| wc | Total Commander Directory Tree |
| wca | WinCatalog Standard Database |
| wcap | Mac OS X Wireless Diagnostics Captured Packets |
| wcat | WinCatalog Standard Database |
| wcb | WinCDR Data |
| wcd | Microsoft Works Calendar |
| wcf | FRAMES Water Concentration File |
| wck | WaterCAD Data |
| wcl | WinCatalog Light Database |
| wcrypt | Webcrypto-crypt Encrypted Data |
| wcs | WhopSee Compressed Skin |
| wct | WCT Reader Index File |
| wcu | CueCard Saved Flashcards Data |
| wcxf | WorldCard Mobile Exchange Data |
| wcz | Chameleon Clock Wallpaper |
| wd3 | Offline Explorer Data |
| wda | AutoCAD Electrical Project User Attributes Data |
| wdc | WinDaq Waveform Browser Data |
| wdh | WinDaq High Resolution Data |