System file extensions

System file extension list

File extensions used for computer operating systems internal use and are required for right and heathy run of any operating system.

System files is very important group of file formats, which are used by computer operating systems. If any of these files are missing or corrupted, operating system don't work correctly or not start at all. For prevention have many system files set file attribute to hidden or don't be visible for users. Basic system files are incompatible between operating systems and operating systems have own native binary formats for them. For example Microsoft Windows system files couldn't work as system files in Linux or MAC OS X.

Exception forms for example device drivers. Holds the same condition Microsoft Windows device drivers are not compatible with Linux or MAC OS X, but the same driver could be used in some versions of Microsoft Windows. For example Windows 95/98/Me have the same driver file format, drivers for Windows 95 could often works in newer Windows Me.

Most widely used system file extensions are sys, drv, dll, inf etc.

More experienced users can configure Windows Explorer or file manager to show hidden and system files. But be very careful, any damage of important system files can lead to malfunction or an unstable operating system.

Extension	File type description
file extension $03	MS-DOS pipe file
file extension 0	PSERVER printer queue information file
file extension 000	CHKDSK found folder
file extension 001	Unix system file
file extension 1pa	Microsoft Windows file
file extension 286	Microsoft Windows virtual device driver
file extension 32s	Win32s file
file extension 386	Microsoft Windows virtual device driver
file extension aa	Unix File
file extension aad	FreeBSD file
file extension acm	Audio Compression Module add-on
file extension acv	Compress and decompress audio data
file extension acv	Microsoft DirectX audio code C file
file extension ad	UNIX application default resource file
file extension add	Adapter Device Driver
file extension add	OS/2 adapter drivers used in the boots process
file extension adm	Administrator policy template
file extension adv	Gravis Ultrasound virtual device driver
file extension ann	Microsoft Windows Help annotation
file extension apd	Adobe PageMaker printer description
file extension apd	IBM Lotus printer driver
file extension ar	Linux/Unix command library
file extension aslquery	MAC OS X console query
file extension aws	ActiveWords System
file extension ax	ATI DA interface handler
file extension b	LILO Boot Loader image
file extension bcs	Microsoft Windows 95 browse information file
file extension blf	BancTec scanner driver
file extension blf	Microsoft Windows Vista file
file extension bmk	Bookmark file from Windows help
file extension bpd	Pscript Binary PostScript printer description file
file extension bsd	FacetWin bitwise backup set file
file extension bup	Brother Embroidery system file
file extension cab	Installation File For Windows Mobile
file extension cat	Microsoft Security Catalog file
file extension cdfs	Microsoft Windows compact disk file system
file extension cdm	Novell NetWare disk drivers NPA
file extension cin	OS/2 change control file
file extension cmd	DOS CP/M command file
file extension cmg	cramfs ROM file system package
file extension cnf	Microsoft Windows 95 speed dial file
file extension cnm	Microsoft Windows application menu options and setup file
file extension cnt	Windows or other system content files
file extension cnv	Microsoft Word conversion file
file extension com	Psion Organiser CommsLink setup file
file extension cpi	Microsoft Windows or DOS international code page
file extension cpi	Microsoft MS-DOS code page information file
file extension cpl	Microsoft Windows Control Panel extension
file extension cpy	Atari Ramdrive CPY commands
file extension ctfsys	OS X Mach Kernel system file
file extension cub	Validation module
file extension dan	AMD ATI Radeon video driver
file extension dat	Windows registry hive
file extension dbl	WindowsXP product activation file
file extension ddp	OS/2 device driver profile file
file extension desklINK	Desk Link
file extension dev	Windows Device Driver file
file extension dif	OS/2 display information file
file extension dir	Directory indicator
file extension dis	Soundweb firmware file
file extension dl	Masked Dynamic Link Library file
file extension dlm	Dynamic Link module
file extension dmp	Memory dump, screen dump, junk files...
file extension drv	Device Driver
file extension ds	Desktop Korn Shell file
file extension dsk	Novell NetWare disk driver
file extension dsn	Microsoft OLE DB Provider for ODBC drivers
file extension dsp	Dr.Halo graphics display driver
file extension dss	Screensaver file
file extension DS_Store	Macintosh OS X Folder Information
file extension dt	Macintosh file data fork
file extension dtp	SecurDesk! desktop file
file extension dvd	DOS Device Driver File
file extension dvr	Device driver file
file extension ecw	System Dll file
file extension edg	EdG command file
file extension env	HP-95 environment file
file extension evt	Microsoft Windows evnent log file
file extension ffa	MS Office Find Fast status file
file extension ffl	MS Office Find Fast document list
file extension ffo	MS Office Find Fast document properties cache
file extension fin	AMD ATI Radeon video driver
file extension fll	Visual FoxPro dynamic link library
file extension flt	OS/2 Warp Filter Device Driver
file extension folder	Microsoft Windows Explorer folder file
file extension fs	NetBSD system file
file extension fseventsd	MAC OS X file
file extension ftg	Windows Help file
file extension fts	Windows Help index
file extension gadget	Windows sidebar gadget file
file extension gpd	Microsoft Windows XP printer driver file
file extension grb	MS-DOS Shell Monitor file
file extension group	Linux file
file extension grp	Windows Program Group file
file extension gwp	Greetings WorkShop file
file extension h1c	Windows Vista file related to Assistance Platform (AP) help
file extension h1f	Microsoft Windows Assistance Platform client help file
file extension h1k	Keyword index - Microsoft Windows Assistance Platform client help related file
file extension h1s	Microsoft Windows Assistance Platform client help file
file extension h1t	Microsoft Windows Assistance Platform client help related file
file extension h1v	Task metadata file - Microsoft Windows Assistance Platform client help related file
file extension ham	Novell NetWare disk drivers NPA
file extension HDMP	Windows Heap Dump file
file extension hhc	HTML Help Table Of Contents file
file extension hhk	MS HTML Help Index
file extension hiv	Windows NT Registry Hive
file extension hlp	Microsoft help file
file extension htt	Microsoft HyperText Template file
file extension hxi	Microsoft Help compiled storage file
file extension hxs	Microsoft Help compiled storage file
file extension icap	Internet preference file
file extension idx	Index file
file extension idx	Corel QuickFinder index
file extension ifs	OS/2 installable file system
file extension il	Icon library file
file extension inf	Autostart CDROM file
file extension inf	Windows installation script
file extension ins	Microsoft Windows Internet Naming Service
file extension ion	4DOS description file
file extension kbd	Keyboard Script File Layout
file extension kext	Kernel extension
file extension key	Keyboard definition file
file extension key	Security file
file extension key	Microsoft Windows 7 registry key
file extension kmd	Clicker module output
file extension lbr	Lotus 1-2-3 display driver
file extension lck	Lock file (database access control)
file extension lex	Lex or Flex file
file extension lgh	Microsoft Windows Applog file
file extension lgs	Microsoft Windows application log file
file extension linux	Linux file
file extension ln	UNIX lint file
file extension localized	MAC OS X file
file extension lock	Lock file
file extension ls	Unix directory file
file extension man	Microsoft Windows 2000/XP mandatory user profile
file extension manifest	Windows Visual Stylesheet XML definition file
file extension manifest	Manifest files
file extension manifest	Microsoft .NET Framework application manifest file
file extension mapimail	Send mail file
file extension mbr	AS/400 physical file member
file extension mcp	Amiga MUI preference class or library
file extension mdmp	Microsoft Windows minidump file
file extension mfl	Microsoft Windows XP System32 WBEM file
file extension mft	NTFS master file table file
file extension mkext	Mac OS X Mach kernel extension memory cache
file extension mlb	Microsoft Windows Mobile media library file
file extension mnu	MS DOS mouse menu file
file extension mob	Device definition (PEN Windows)
file extension mod	MS DOS implementing support for Windows DLL's file
file extension mod	Microsoft Windows kernel module
file extension mos	System Dos62 file
file extension mot	Linux load instructions file
file extension mpa	Palm memo file
file extension mpkg	Meta package file
file extension mrg	Merge file
file extension msc	Microsoft management console control file
file extension mso	Word OLE web page storage stream
file extension mso	ActiveMime object file
file extension msp	Windows Installer patch file
file extension msstyles	WIN Resources Themes Luna file
file extension mui	MultiLanguage Windows resource file
file extension mui	Amiga MUI default class/library
file extension mydocs	Send to file
file extension nex	Nexcon system file
file extension nib	Interface Builder user interface resources
file extension nib	Adobe AIR file
file extension nlm	Novell Netware loadable module
file extension nor	ATI Radeon driver file
file extension nst	Nokia Star Torrent system file
file extension ocx	ActiveX control file
file extension opx	OPL extension DLL
file extension osc	Remote Installation Services client installation wizard file
file extension oth	Microsoft PowerToys Explorer tool
file extension ov2	Overlay file
file extension ovl	Overlay file
file extension par	Windows 3.x swap file
file extension part1	NetObjects Fusion system file
file extension payload	Microsoft Windows Mobile file
file extension pbd	PowerBuilder dynamic link library
file extension pcf	Microsoft Source Profiler profiler command file
file extension pcm	LaserJet Printer Cartridge Metric for printer driver
file extension pdf	Print device information (Netware)
file extension pdf	Printer description (QuarkXpress)
file extension pdr	Windows Port Driver, Device Driver
file extension pf	Windows prefetch file
file extension pid	Creative Driver File
file extension pkg	Microsoft Developer Studio application extension
file extension pkg	Apple MAC OS X installer file
file extension plt	EPOC software platform file
file extension plt	HP Graphics Language file (plotter)
file extension pol	Policy Windows 95 network setup file
file extension pol	Windows policy file
file extension prefpane	Mac OS X System Preference Pane
file extension prf	dBase IV printer driver
file extension prf	Microsoft Profiler output
file extension prf	Microsoft Windows system file
file extension prf	MicroImages print driver file
file extension prs	Norton Viewer DLL file
file extension psf	Windows Server Update Services patch storage file
file extension qpr	OS/2 print queue device driver
file extension qtz	MAC OS X Quartz graphics file
file extension que	PDP-10 queue file
file extension rdl	Symbian recogniser library
file extension ref	Atari ST guide ref links
file extension rel	Nintendo Wii relocatable module
file extension rge	Inno setup registry entries file
file extension rgu	Microsoft Windows Mobile registry entry
file extension rsrc	MAC OS X resource file
file extension rtb	NAT proxy servers file
file extension rtp	Microsoft software update file
file extension sa	UNIX stub library
file extension Savedsearch	Spotlight Saved Search
file extension saver	Mac OS X Screen Saver
file extension scc	Visual SourceSafe control file
file extension scd	Systems Management Server (SMS) site control file deletion
file extension scr	Windows screensaver file
file extension scr	DOS DEBUG input file
file extension sdb	Custom Application Compatibility Database
file extension sdr	QuickView Pro for DOS soundcard driver
file extension sf	OS/2 work place shell attribute storage file
file extension sfc	Microsoft Windows system file check file
file extension sfcache	ReadyBoost cache file
file extension sfs	Squashfs file
file extension shd	Microsoft Windows shadow spooler file
file extension shs	Microsoft Windows 95/98 clipboard
file extension sid	Microsoft Systems Management Server (SMS) software inventory delta
file extension sif	Microsoft Windows NTsetup installation file
file extension sl	HP-UX shared library
file extension sparc	SunOS 4 file
file extension spl	Microsoft Windows printing spool file
file extension sps	Sprint screen driver
file extension ss	Screen saver file
file extension str	Screensaver file
file extension supported	MAC OS X file
file extension swp	Swap file
file extension sys	System file
file extension sys	PDP-10 system file
file extension sys	System configuration
file extension sys	System device driver
file extension tbl	Dynamic link library
file extension tbl	OS/2 table of values
file extension tbr	Norton Desktop custom toolbar file
file extension tbs	TuneUp style boot screen file
file extension tlb	OLE type library
file extension tsk	Microsoft Windows system32 file
file extension twd	System file
file extension uce	Microsoft Windows XP system32 file
file extension upd	Universal print driver
file extension user	Linux file
file extension vap	NetWare 2.xx value added process file
file extension vcn	NCDrive Vacon NX system software file
file extension vga	VGA display driver
file extension vgd	VGA CADD display driver
file extension vid	Screen device driver (MS DOS/Word)
file extension vid	Microsoft DOS video driver
file extension vid	Monitor control file
file extension vtd	Custom virtual device driver
file extension vxd	Microsoft Windows virtual device driver
file extension wbs	Webshots screensaver
file extension wdgt	Dashboard widget
file extension wdr	Psion Series 3 printer driver
file extension woa	Windows 3.x swap file
file extension wpd	Windows printer driver
file extension wpx	Adobe printer description for Postscript printing
file extension wss	Microsoft Windows Sound System file
file extension xms	Microsoft eXtended Memory Specification (XMS)
file extension zlc	AAICWpro/ZoneAlarm Mailsafe renamed .inf file
file extension zmb	ZoneAlarm Mailsafe renamed .DLL file
file extension zmd	ZoneAlarm Mailsafe file
file extension zme	ZoneAlarm Mailsafe file
file extension _dl	Dynamic Link Library DLL file form