| mcc | mcd | mch | mci | mcp |
| mcr | mcs | mcw | md | md1 |
| md2 | md5 | mda | mdb | mde |
| mdf | mdi | mdl | mdn | mds |
| mdw | w92 | w93 | w94 | w95 |
| w96 | w97 | w98 | w99 | wa~ |
| wab | wad | wag | wal | was |
| wav | wax | wb1 | wb2 | wba |
| wbk | wbl | wbmp | wbr | wbt |
| wcm | wcs | wct | wcx | wdb |
| wdf | wdg | wdl | wdp | wdx |
| web | webpnp | wed | wfb | wfd |
| wfm | wfn | wfp | wfx | wg! |
| wgp | wht | wid | wif | wil |
| win | wit | wix | wiz | wjj |
| wk1 | wk3 | wk4 | wks | wld |
| wlf | wlg | wll | wlx | wm |
| wma | wmd | wmdb | wmf | wml |
| wmlc | wmls | wmlsc | wmn | wmp |
| wms | wmv | wmx | wmz | wnd |
| wo2 | wo3 | wo4 | wor | acl |
| acm | acp | acr | acs | act |
| acv | acw | ad | ada | adb |
| adc | add | ade | adf | adi |
| 文件扩展名 是操作系统用来标志文件格式的一种机制。通常来说，一个扩展名是跟在文件名后面的，由一个分隔符分隔。在一个像“readme.txt”的文件名中，readme是文件名，txt为扩展名，表示这个文件是一个纯文本文件。 |