Browse file extensions by file type category:

System file icon System file type extensions
(272 file extension database entries)

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

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.

ExtensionFile type description
$03 file icon file extension $03MS-DOS pipe file
0 file icon file extension 0PSERVER printer queue information file
000 file icon file extension 000CHKDSK found folder
001 file icon file extension 001Unix system file
1pa file icon file extension 1paMicrosoft Windows file
286 file icon file extension 286Microsoft Windows virtual device driver
32s file icon file extension 32sWin32s file
386 file icon file extension 386Microsoft Windows virtual device driver
aa file icon file extension aaUnix File
aad file icon file extension aadFreeBSD file
acm file icon file extension acmAudio Compression Module add-on
acv file icon file extension acvCompress and decompress audio data
acv file icon file extension acvMicrosoft DirectX audio code C file
ad file icon file extension adUNIX application default resource file
add file icon file extension addAdapter Device Driver
add file icon file extension addOS/2 adapter drivers used in the boots process
adm file icon file extension admAdministrator policy template
adv file icon file extension advGravis Ultrasound virtual device driver
ann file icon file extension annMicrosoft Windows Help annotation
apd file icon file extension apdAdobe PageMaker printer description
apd file icon file extension apdIBM Lotus printer driver
ar file icon file extension arLinux/Unix command library
aslquery file icon file extension aslqueryMAC OS X console query
aws file icon file extension awsActiveWords System
ax file icon file extension axATI DA interface handler
b file icon file extension bLILO Boot Loader image
bcs file icon file extension bcsMicrosoft Windows 95 browse information file
blf file icon file extension blfBancTec scanner driver
blf file icon file extension blfMicrosoft Windows Vista file
bmk file icon file extension bmkBookmark file from Windows help
bpd file icon file extension bpdPscript Binary PostScript printer description file
bsd file icon file extension bsdFacetWin bitwise backup set file
bup file icon file extension bupBrother Embroidery system file
cab file icon file extension cabInstallation File For Windows Mobile
cat file icon file extension catMicrosoft Security Catalog file
cdfs file icon file extension cdfsMicrosoft Windows compact disk file system
cdm file icon file extension cdmNovell NetWare disk drivers NPA
cin file icon file extension cinOS/2 change control file
cmd file icon file extension cmdDOS CP/M command file
cmg file icon file extension cmgcramfs ROM file system package
cnf file icon file extension cnfMicrosoft Windows 95 speed dial file
cnm file icon file extension cnmMicrosoft Windows application menu options and setup file
cnt file icon file extension cntWindows or other system content files
cnv file icon file extension cnvMicrosoft Word conversion file
com file icon file extension comPsion Organiser CommsLink setup file
cpi file icon file extension cpiMicrosoft Windows or DOS international code page
cpi file icon file extension cpiMicrosoft MS-DOS code page information file
cpl file icon file extension cplMicrosoft Windows Control Panel extension
cpy file icon file extension cpyAtari Ramdrive CPY commands
ctfsys file icon file extension ctfsysOS X Mach Kernel system file
cub file icon file extension cubValidation module
dan file icon file extension danAMD ATI Radeon video driver
dat file icon file extension datWindows registry hive
dbl file icon file extension dblWindowsXP product activation file
ddp file icon file extension ddpOS/2 device driver profile file
desklINK file icon file extension desklINKDesk Link
dev file icon file extension devWindows Device Driver file
dif file icon file extension difOS/2 display information file
dir file icon file extension dirDirectory indicator
dis file icon file extension disSoundweb firmware file
dl file icon file extension dlMasked Dynamic Link Library file
dlm file icon file extension dlmDynamic Link module
dmp file icon file extension dmpMemory dump, screen dump, junk files...
drv file icon file extension drvDevice Driver
ds file icon file extension dsDesktop Korn Shell file
dsk file icon file extension dskNovell NetWare disk driver
dsn file icon file extension dsnMicrosoft OLE DB Provider for ODBC drivers
dsp file icon file extension dspDr.Halo graphics display driver
dss file icon file extension dssScreensaver file
DS_Store file icon file extension DS_StoreMacintosh OS X Folder Information
dt file icon file extension dtMacintosh file data fork
dtp file icon file extension dtpSecurDesk! desktop file
dvd file icon file extension dvdDOS Device Driver File
dvr file icon file extension dvrDevice driver file
ecw file icon file extension ecwSystem Dll file
edg file icon file extension edgEdG command file
env file icon file extension envHP-95 environment file
evt file icon file extension evtMicrosoft Windows evnent log file
ffa file icon file extension ffaMS Office Find Fast status file
ffl file icon file extension fflMS Office Find Fast document list
ffo file icon file extension ffoMS Office Find Fast document properties cache
fin file icon file extension finAMD ATI Radeon video driver
fll file icon file extension fllVisual FoxPro dynamic link library
flt file icon file extension fltOS/2 Warp Filter Device Driver
folder file icon file extension folderMicrosoft Windows Explorer folder file
fs file icon file extension fsNetBSD system file
fseventsd file icon file extension fseventsdMAC OS X file
ftg file icon file extension ftgWindows Help file
fts file icon file extension ftsWindows Help index
gadget file icon file extension gadgetWindows sidebar gadget file
gpd file icon file extension gpdMicrosoft Windows XP printer driver file
grb file icon file extension grbMS-DOS Shell Monitor file
group file icon file extension groupLinux file
grp file icon file extension grpWindows Program Group file
gwp file icon file extension gwpGreetings WorkShop file
h1c file icon file extension h1cWindows Vista file related to Assistance Platform (AP) help
h1f file icon file extension h1fMicrosoft Windows Assistance Platform client help file
h1k file icon file extension h1kKeyword index - Microsoft Windows Assistance Platform client help related file
h1s file icon file extension h1sMicrosoft Windows Assistance Platform client help file
h1t file icon file extension h1tMicrosoft Windows Assistance Platform client help related file
h1v file icon file extension h1vTask metadata file - Microsoft Windows Assistance Platform client help related file
ham file icon file extension hamNovell NetWare disk drivers NPA
HDMP file icon file extension HDMPWindows Heap Dump file
hhc file icon file extension hhcHTML Help Table Of Contents file
hhk file icon file extension hhkMS HTML Help Index
hiv file icon file extension hivWindows NT Registry Hive
hlp file icon file extension hlpMicrosoft help file
htt file icon file extension httMicrosoft HyperText Template file
hxi file icon file extension hxiMicrosoft Help compiled storage file
hxs file icon file extension hxsMicrosoft Help compiled storage file
icap file icon file extension icapInternet preference file
idx file icon file extension idxIndex file
idx file icon file extension idxCorel QuickFinder index
ifs file icon file extension ifsOS/2 installable file system
il file icon file extension ilIcon library file
inf file icon file extension infAutostart CDROM file
inf file icon file extension infWindows installation script
ins file icon file extension insMicrosoft Windows Internet Naming Service
ion file icon file extension ion4DOS description file
kbd file icon file extension kbdKeyboard Script File Layout
kext file icon file extension kextKernel extension
key file icon file extension keyKeyboard definition file
key file icon file extension keySecurity file
key file icon file extension keyMicrosoft Windows 7 registry key
kmd file icon file extension kmdClicker module output
lbr file icon file extension lbrLotus 1-2-3 display driver
lck file icon file extension lckLock file (database access control)
lex file icon file extension lexLex or Flex file
lgh file icon file extension lghMicrosoft Windows Applog file
lgs file icon file extension lgsMicrosoft Windows application log file
linux file icon file extension linuxLinux file
ln file icon file extension lnUNIX lint file
localized file icon file extension localizedMAC OS X file
lock file icon file extension lockLock file
ls file icon file extension lsUnix directory file
man file icon file extension manMicrosoft Windows 2000/XP mandatory user profile
manifest file icon file extension manifestWindows Visual Stylesheet XML definition file
manifest file icon file extension manifestManifest files
manifest file icon file extension manifestMicrosoft .NET Framework application manifest file
mapimail file icon file extension mapimailSend mail file
mbr file icon file extension mbrAS/400 physical file member
mcp file icon file extension mcpAmiga MUI preference class or library
mdmp file icon file extension mdmpMicrosoft Windows minidump file
mfl file icon file extension mflMicrosoft Windows XP System32 WBEM file
mft file icon file extension mftNTFS master file table file
mkext file icon file extension mkextMac OS X Mach kernel extension memory cache
mlb file icon file extension mlbMicrosoft Windows Mobile media library file
mnu file icon file extension mnuMS DOS mouse menu file
mob file icon file extension mobDevice definition (PEN Windows)
mod file icon file extension modMS DOS implementing support for Windows DLL's file
mod file icon file extension modMicrosoft Windows kernel module
mos file icon file extension mosSystem Dos62 file
mot file icon file extension motLinux load instructions file
mpa file icon file extension mpaPalm memo file
mpkg file icon file extension mpkgMeta package file
mrg file icon file extension mrgMerge file
msc file icon file extension mscMicrosoft management console control file
mso file icon file extension msoWord OLE web page storage stream
mso file icon file extension msoActiveMime object file
msp file icon file extension mspWindows Installer patch file
msstyles file icon file extension msstylesWIN Resources Themes Luna file
mui file icon file extension muiMultiLanguage Windows resource file
mui file icon file extension muiAmiga MUI default class/library
mydocs file icon file extension mydocsSend to file
nex file icon file extension nexNexcon system file
nib file icon file extension nibInterface Builder user interface resources
nib file icon file extension nibAdobe AIR file
nlm file icon file extension nlmNovell Netware loadable module
nor file icon file extension norATI Radeon driver file
nst file icon file extension nstNokia Star Torrent system file
ocx file icon file extension ocxActiveX control file
opx file icon file extension opxOPL extension DLL
osc file icon file extension oscRemote Installation Services client installation wizard file
oth file icon file extension othMicrosoft PowerToys Explorer tool
ov2 file icon file extension ov2Overlay file
ovl file icon file extension ovlOverlay file
par file icon file extension parWindows 3.x swap file
part1 file icon file extension part1NetObjects Fusion system file
payload file icon file extension payloadMicrosoft Windows Mobile file
pbd file icon file extension pbdPowerBuilder dynamic link library
pcf file icon file extension pcfMicrosoft Source Profiler profiler command file
pcm file icon file extension pcmLaserJet Printer Cartridge Metric for printer driver
pdf file icon file extension pdfPrint device information (Netware)
pdf file icon file extension pdfPrinter description (QuarkXpress)
pdr file icon file extension pdrWindows Port Driver, Device Driver
pf file icon file extension pfWindows prefetch file
pid file icon file extension pidCreative Driver File
pkg file icon file extension pkgMicrosoft Developer Studio application extension
pkg file icon file extension pkgApple MAC OS X installer file
plt file icon file extension pltEPOC software platform file
plt file icon file extension pltHP Graphics Language file (plotter)
pol file icon file extension polPolicy Windows 95 network setup file
pol file icon file extension polWindows policy file
prefpane file icon file extension prefpaneMac OS X System Preference Pane
prf file icon file extension prfdBase IV printer driver
prf file icon file extension prfMicrosoft Profiler output
prf file icon file extension prfMicrosoft Windows system file
prf file icon file extension prfMicroImages print driver file
prs file icon file extension prsNorton Viewer DLL file
psf file icon file extension psfWindows Server Update Services patch storage file
qpr file icon file extension qprOS/2 print queue device driver
qtz file icon file extension qtzMAC OS X Quartz graphics file
que file icon file extension quePDP-10 queue file
rdl file icon file extension rdlSymbian recogniser library
ref file icon file extension refAtari ST guide ref links
rel file icon file extension relNintendo Wii relocatable module
rge file icon file extension rgeInno setup registry entries file
rgu file icon file extension rguMicrosoft Windows Mobile registry entry
rsrc file icon file extension rsrcMAC OS X resource file
rtb file icon file extension rtbNAT proxy servers file
rtp file icon file extension rtpMicrosoft software update file
sa file icon file extension saUNIX stub library
Savedsearch file icon file extension SavedsearchSpotlight Saved Search
saver file icon file extension saverMac OS X Screen Saver
scc file icon file extension sccVisual SourceSafe control file
scd file icon file extension scdSystems Management Server (SMS) site control file deletion
scr file icon file extension scrWindows screensaver file
scr file icon file extension scrDOS DEBUG input file
sdb file icon file extension sdbCustom Application Compatibility Database
sdr file icon file extension sdrQuickView Pro for DOS soundcard driver
sf file icon file extension sfOS/2 work place shell attribute storage file
sfc file icon file extension sfcMicrosoft Windows system file check file
sfcache file icon file extension sfcacheReadyBoost cache file
sfs file icon file extension sfsSquashfs file
shd file icon file extension shdMicrosoft Windows shadow spooler file
shs file icon file extension shsMicrosoft Windows 95/98 clipboard
sid file icon file extension sidMicrosoft Systems Management Server (SMS) software inventory delta
sif file icon file extension sif Microsoft Windows NTsetup installation file
sl file icon file extension slHP-UX shared library
sparc file icon file extension sparcSunOS 4 file
spl file icon file extension splMicrosoft Windows printing spool file
sps file icon file extension spsSprint screen driver
ss file icon file extension ssScreen saver file
str file icon file extension strScreensaver file
supported file icon file extension supportedMAC OS X file
swp file icon file extension swpSwap file
sys file icon file extension sysSystem file
sys file icon file extension sysPDP-10 system file
sys file icon file extension sysSystem configuration
sys file icon file extension sysSystem device driver
tbl file icon file extension tblDynamic link library
tbl file icon file extension tblOS/2 table of values
tbr file icon file extension tbrNorton Desktop custom toolbar file
tbs file icon file extension tbsTuneUp style boot screen file
tlb file icon file extension tlbOLE type library
tsk file icon file extension tskMicrosoft Windows system32 file
twd file icon file extension twdSystem file
uce file icon file extension uceMicrosoft Windows XP system32 file
upd file icon file extension updUniversal print driver
user file icon file extension userLinux file
vap file icon file extension vapNetWare 2.xx value added process file
vcn file icon file extension vcnNCDrive Vacon NX system software file
vga file icon file extension vgaVGA display driver
vgd file icon file extension vgdVGA CADD display driver
vid file icon file extension vidScreen device driver (MS DOS/Word)
vid file icon file extension vidMicrosoft DOS video driver
vid file icon file extension vidMonitor control file
vtd file icon file extension vtdCustom virtual device driver
vxd file icon file extension vxdMicrosoft Windows virtual device driver
wbs file icon file extension wbsWebshots screensaver
wdgt file icon file extension wdgtDashboard widget
wdr file icon file extension wdrPsion Series 3 printer driver
woa file icon file extension woaWindows 3.x swap file
wpd file icon file extension wpdWindows printer driver
wpx file icon file extension wpxAdobe printer description for Postscript printing
wss file icon file extension wssMicrosoft Windows Sound System file
xms file icon file extension xmsMicrosoft eXtended Memory Specification (XMS)
zlc file icon file extension zlcAAICWpro/ZoneAlarm Mailsafe renamed .inf file
zmb file icon file extension zmbZoneAlarm Mailsafe renamed .DLL file
zmd file icon file extension zmdZoneAlarm Mailsafe file
zme file icon file extension zmeZoneAlarm Mailsafe file
_dl file icon file extension _dlDynamic Link Library DLL file form


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