As you know, Windows system files are divided into many types based on different formats and purposes. For ease of management and identification, file names are differentiated by extensions, that is, the file name format is: main file name. extension. In this way, the file type can be determined based on the file extension to know its format and purpose. For example:
File Name 1. Doc extension Doc indicates that this file is a Microsoft Word document,
File name 2. The extension of XLS indicates that this file is a Microsoft Excel worksheet,
File Name 3. The BMP extension indicates that this file is a BMP image,
File Name 4. The MP3 extension indicates that the file is in MP3 format,
File name 5. the mpeg extension MPEG indicates that this file is a movie file (mPEG ).
The following lists the Windows system file extensions and their classification tables for reference:
1. 323 H.323 Internet telephone technology
2. 386 Virtual Device Driver
3. ACA Microsoft Agent character file (HTTP format)
4. ACF Microsoft Agent character file (HTTP format)
5. ACG Microsoft Agent preview File
6. The ACL automatically corrects list files.
7. ACS Microsoft Agent character file
8. ACW Auxiliary Function Wizard settings
9. Ade Microsoft Access Project Extension
10. ADN Microsoft Access blank Project template
11. ADP Microsoft Access Project
12. aif aiff format sound
13. aifc aiff format sound
14. AIFF format sound
15. ANI animation cursor
16. ASA activity server documentation
17. asd asf Stream Description File
18. ASF Windows Media Audio/Video Files
19. ASP activity server documentation
20. ASX Windows Media Audio/Video shortcuts
21. AU format sound
22. AUDIOCD AudioCD
23. AVI Video Editing
24. AW response wizard File
25. BKF Windows Backup File
26. BLG Performance Monitor File
27. BMP Image
28. CAT security catalog
29. cda cd audio tracks
30. CDF channel File
31. CDX active server documentation
32. CER Security Certificate
33. CHK restored file fragments
34. CHM Compiled HTML Help File
35. CLP clipboard
36. CNF quick dialing
37. col html Help File
38. CPL Control Panel Extension
39. CRL Certificate Revocation List
40. CRT Security Certificate
41. CSS Cascading Style Sheet document
42. CSV Microsoft Excel comma-separated value files
43. CUR cursor
44. DB database files
45. DCS database content source
46. DER Security Certificate
47. Invalid link upload link file
48. DET Office Data File
49. dib bmp Image
50. DIC Text Document
51. DIF Microsoft Excel Data Exchange Format
52. DOC Microsoft Word Document
53. DOCHTML Microsoft Word HTML document
54. DOCMHTML File
55. DOT Microsoft Word template
56. DOTHTML Microsoft Word HTML Template
57. DQY Microsoft Excel ODBC Query file
58. DRV Device Driver
59. DSN Data Source Name
60. DUN Dial-Up Network File
61. DVD
62. ECS Exchange Server content source
63. ELM Microsoft Office topic File
64. EMF images
65. EML Outlook Express mail message
66. exc Text Document
67. FAD Office Data File
68. fav File
69. content source shared by the FCS File
70. FFA file retrieval index
71. FFL file retrieval index
72. FFT file retrieval index
73. FFX file retrieval index
74. Fon font file
75. fpdoclib Microsoft FrontPage Document Library
76. fphomeop Microsoft FrontPage home page open
77. fphomepg Microsoft FrontPage Homepage
78. fphtml Microsoft FrontPage HTML document
79. fplist Microsoft FrontPage list
80. fpnopub Microsoft FrontPage dont publish
81. fpopen Microsoft FrontPage open the file
82. fpsurvey Microsoft FrontPage Survey
83. fpweb files
84. FRG File
85. GIF images
86. Gra Microsoft Graph chart
87. GRP Microsoft Program Group
88. HLP Help File
89. HOL Microsoft Outlook Holidays
90. HT Super Terminal File
91. hta html Application
92. HTC File
93. htm html Document
94. HTML Document
95. HTT HyperText Template
96. htx html template for Internet databases
97. ICC configuration file
98. icm icc configuration file
99. ICO icon
100. ICS iCalendar File
101. IDC files
102. III Intel IPhone compatibility
103. INF installation information
104. INI configuration settings
105. INS Internet Communication Settings
106. IQY Microsoft Excel Web query file
107. ISP Internet Communication Settings
108. ITS Internet Document Set
109. ITSS Microsoft Infotech Storage System File
110. IVF Indeo video files
111. jfif jpeg Image
112. JOB task object
113. Jod Microsoft. Jet. oledb.4.0
114. jpe JPEG Image
115. JPEG Image
116. jpg JPEG Image
117. js JScript script file
118. JSE JScript Encoded Script File
119. LDB Microsoft Access records lock Information
120. Lex dictionary file
121. Log Text Document
122. LWV Microsoft linguistically enhanced sound file
123. m1v movie file (mPEG)
124. m3u M3U File
125. Mad Microsoft Access Module shortcut
126. MAF Microsoft Access Form shortcut
127. Mag Microsoft Access chart shortcut
128. Mam Microsoft Access macro shortcut
129. mapimail File
130. Maq Microsoft Access query shortcuts
131. Mar Microsoft Access Report shortcut
132. Mas Microsoft Access Stored Procedure shortcut
133. Mat Microsoft Access Table shortcuts
134. MAU File
135. MAV Microsoft Access view shortcuts
136. MAW Microsoft Access Data Access page shortcut
137. MDA Microsoft Access add-on
138. MDB Microsoft Access Application
139. MDBHTML Microsoft Access HTML document
140. MDE Microsoft Access MDE Database
141. MDN Microsoft Access blank database template
142. MDT Microsoft Access add-on Data
143. MDW Microsoft Access workgroup Information
144. MDZ Microsoft Access Database Wizard Template
145. MGC media directory file
146. mht mhtml Document
147. MHTML Document
148. mid midi Sequence
149. MIDI Sequence
150. MML media directory file
151. MMM media editing
152. MMW media directory file
153. MP2 movie file (MPEG)
154. MP2V movie file (MPEG)
155. MP3 audio format
156. MPA movie file (MPEG)
157. MPE movie file (MPEG)
158. MPEG movie file (MPEG)
159. MPF Media Package file
160. MPG movie file (MPEG)
161. MPV2 movie file (MPEG)
162. MSC Microsoft General Management Document
163. MSG Outlook project
164. MSI Windows Installer package
165. MSP Windows Installer patch
166. MSRCINCIDENT Microsoft Remote Access event
167. MSSTYLES Windows visual style File
168. MSWMM Windows Movie Maker Project
169. NCS Lotus Notes content source
170. NFO MSInfo document
171. NICK Office Data File
172. NK2 Office Data File
173. NMW Microsoft NetMeeting T126 compatible whiteboard document
174. NWS Outlook Express News
175. OBD File
176. OBT File
177. OBZ File
178. OCX ActiveX Control
179. ODC Microsoft Office Data Connection
180. ODCCUBEFILE File
181. ODCDATABASEFILE
182. ODCNEWFILE
183. ODCTABLEFILE
184. OFT Outlook project template
185. OPC Microsoft Cleanup Wizard File
186. OPS Office 10 setting file
187. OQY Microsoft Excel OLAP query file
188. Search for OSS Office
189. OST Office data file
190. OTF OpenType Font File
191. P10 Certificate Application
192. P12 Personal Information Exchange
193. P7B PKCS #7 Certificate
194. P7C digital identification file
195. P7M PKCS #7 MIME message
196. P7R PKCS #7 Certificate
197. P7S PKCS #7 Signature
198. PAB Office Data File
199. PBK dialing phone book
200. PCB File
201. PCD photo CD image
202. PCX Image
203. PFM type 1 Font File
204. pfx personal information exchange
205. Pip Microsoft Office settings file
206. PKO public key security object
207. PMA Performance Monitor File
208. PMC Performance Monitor File
209. PML Performance Monitor File
210. PMR Performance Monitor File
211. PMW Performance Monitor File
212. PNG Image
213. Pot Microsoft PowerPoint template
214. pothtml Microsoft PowerPoint HTML Template
215. PPA Microsoft PowerPoint add-on
216. PPS Microsoft PowerPoint slides
217. Microsoft PowerPoint presentation
218. ppthtml Microsoft PowerPoint HTML document
219. pptmhtml File
220. PRF msrating. dll,-3001
221. Pst Office Data File
222. psw password backup
223. pwz Microsoft PowerPoint wizard
224. QDs directory query
225. Rat msrating. dll,-3000
226. RDP Remote Desktop Connection
227. reg registry key
228. Rmi MIDI Sequence
229. rnk dialing shortcut
230. rqy Microsoft Excel ole db Query file
231. RTF Format
232. rwz Office Data File
233. SC2 Microsoft schedule + application
234. SCD Microsoft schedule + application
235. Sch Microsoft schedule + application
236. SCP Text Document
237. SCT Windows Script component
238. SDB appfix package
239. SHB inserts shortcuts into the document
240. Shs fragment object
241. shtm HTML document
242. shtml HTML document
243. SLK Microsoft Excel SLK data import format
244. sll File
245. snd au format sound
246. SNP Snapshot File
247. spc pkcs #7 Certificate
248. SPL Shockwave Flash Object
249. SST Microsoft series certificate Storage
250. STF Microsoft Installation File
251. STL Certificate Trust List
252. stm html Document
253. SWF Shockwave Flash Object
254. SYS System File
255. TCS Tahoe Server content source
256. THEME Windows THEME File
257. TIF Image
258. tiff tif Image
259. TTC TrueType Collection font file
260. TTF TrueType font file
261. TXT text document
262. UDL Microsoft Data Link
263. ULS Internet location service
264. URL Internet shortcuts
265. VBE VBScript Encoded Script File
266. VBS VBScript Script File
267. VCF vCard File
268. VCS vCalendar File
269. VXD Virtual Device Driver
270. WAB digital identification file
271. WAV waveform sound
272. WAX Windows Media Audio shortcuts
273. WBK Microsoft Word backup document
274. WCS Web site content source
275. WEB Office Data Files
276. WEBPNP Webpnp
277. WHT Microsoft NetMeeting old whiteboard document
278. WIZ Microsoft Word Wizard
279. WIZHTML Microsoft Access HTML Template
280. WLL File
281. WM Windows Media Audio/Video Files
282. WMA Windows Media Audio Files
283. WMD Windows Media Player download package
284. WMF image
285. WMP Windows Media Player file
286. WMS Windows Media Player appearance File
287. WMV Windows Media Audio/Video Files
288. WMX Windows Media Audio/Video shortcuts
289. WMZ Windows Media Player appearance package
290. WPS file
291. WRI write document
292. WSC Windows Script component
293. WSF Windows Script File
294. wsh Windows Script Host settings file
295. wtx Text Document
296. WVX Windows Media Audio/Video shortcuts
297. xla Microsoft Excel macro Loading
298. xlb Microsoft Excel worksheet
299. xlc Microsoft Excel chart
300. xld Microsoft Excel 5.0 dialog box edit table
301. xlk Microsoft Excel backup file
302. Xll Microsoft Excel Xll macro Loading
303. XLM Microsoft Excel 4.0 macro
304. xls Microsoft Excel worksheet
305. xlshtml Microsoft Excel HTML document
306. xlsmhtml File
307. xlt Microsoft Excel template
308. xlthtml Microsoft Excel HTML Template
309. xlv Microsoft Excel VBA Module
310. xlw Microsoft Excel work zone
311. XML document
312. XNK Exchange shortcut
313. XSL style sheet
314. ZAP software installation settings
315. ZIP compression (zipped) folder