| Extension | 描述 | 檔案格式 |
|---|
| b | Basic language source file | Developer Files |
| b00 | CD Image Segment File. | 磁碟映像檔 |
| b5i | Blindwrite 5 Disk Image File | 磁碟映像檔 |
| b5t | Blindwrite 5 Image Information File | 磁碟映像檔 |
| b6i | Blindwrite Image File | 磁碟映像檔 |
| b6t | Blindwrite 6 Image Information File | 磁碟映像檔 |
| backup | Ad-Aware Reference File | Misc Files |
| bak | Backup File | 備份檔案 |
| bas | BASIC Source Code File | Developer Files |
| bat | Batch File | 執行檔 |
| bba | Settler IV Archive File | 壓縮檔案 |
| bbb | Blackberry Backup File | 備份檔案 |
| bblx | E-Sword Module File | Misc Files |
| bc! | Bitcomet Incompleted Download File | Misc Files |
| bcf | Belarc Advisor Content File | Misc Files |
| bcr | Map & Guide Station File | Misc Files |
| bdm | AVCHD Index File | 視頻檔案 |
| bdmv | Blu-ray information file | 視頻檔案 |
| bfg | CQuickTrans File | Misc Files |
| bfs | Tivoli Storage Manager File | 資料檔 |
| bgl | Babylon Glossary File | Misc Files |
| bh | BlackHole Compressed File | 壓縮檔案 |
| bibtex | BibTeX document | 文字檔 |
| bif | Bioware Resource File | 遊戲檔案 |
| big | Electronic Arts Data File | 遊戲檔案 |
| bik | Bink Video Codec File | 視頻檔案 |
| bikey | Bohemia Interactive Key File | 遊戲檔案 |
| bin | Cuesheet CD/DVD Image | 磁碟映像檔 |
| bk | FrameMaker Book File | 文件檔案 |
| bk | Backup File | Misc Files |
| bkf | Windows Backup File | 備份檔案 |
| bkp | Backup File | 備份檔案 |
| blend | Blender 3D File | 3D Files |
| blf | Bantec Scanner Driver File | Misc Files |
| blf | Windows Registry Recovery File | 系統檔案 |
| blg | Binary Performance Log File | 資料檔 |
| blob | Steam Archive File | 遊戲檔案 |
| bmf | Floor Plan 3D Project File | 3D Files |
| bmk | Windows Help Bookmark File | 文字檔 |
| bmp | BMP File Format | 圖檔 |
| bndl | Bundle File | 系統檔案 |
| bnk | AdLib Instrument Bank File | 聲音檔案 |
| bnp | Sony Video Data File | 視頻檔案 |
| bok | Prostores Dynamic Web Page File | Layout Files |
| boot | Installshield File | Misc Files |
| box | Mailbox File | Misc Files |
| bpl | Borland Package Library File | Developer Files |
| brd | EAGLE Circuit Board Layout File | CAD Files |
| brstm | BRSTM File | 聲音檔案 |
| bsa | Bethseda Softworks Archive File | 遊戲檔案 |
| bsp | Quake Map File | 遊戲檔案 |
| bsv | Bluespec System Verilog File | Developer Files |
| bt! | BitTorrent Partial Download File | Misc Files |
| btn | Buttonware File | 資料檔 |
| bun | Monkey Island 3 Game Archive File | 遊戲檔案 |
| bun | Bundled Audio Files | 聲音檔案 |
| bup | DVD File Backup | 備份檔案 |
| bwa | BlindWrite Disk Image Information File | 3D Files |
| bwi | Blindwrite Disk Image File | 磁碟映像檔 |
| bws | Blindwrite Sub Channel Data File | 磁碟映像檔 |
| bwt | Blindwrite Image File | 磁碟映像檔 |
| bz2 | Bzip2 Compressed File | 壓縮檔案 |