System file extensions

Browse file extensions by file type:

System file type extensions (122 extensions)

File extensions used for operating systems use. File formats itself contains no useful data for common users. Files are required for right and heathy run of any operating system.

[Back to select file type category]

Add file extensions search capability directly into your browser search panel for future use.
Click here to add a new search provider to your browser.

Browsers supporting this feature: Internet Explorer 7, Firefox 2 and above versions.

System filename extensions

File extensions used for operating systems use. File formats itself contains no useful data for common users. Files are required for right and heathy run of any operating system.

Result page: First page | Last page

Extension	File type description
file extension aa	Unix File
file extension adm	Administrator policy template
file extension ani	Animated cursor
file extension ann	Windows Help annotation
file extension ax	ATI DA interface handler
file extension axp	3D software system
file extension bmk	Bookmark file from Windows help
file extension bup	Brother Embroidery system file
file extension cab	Installation File For Windows Mobile
file extension cin	OS/2 Change Control File
file extension cnt	Windows or other system content files
file extension cnv	Microsoft Word conversion file
file extension cpi	Microsoft Windows or DOS international code page
file extension cpi	Microsoft MS-DOS code page information file
file extension cpl	Windows Control Panel extension
file extension dat	Windows registry hive
file extension desklINK	Desk Link
file extension dev	Windows Device Driver File
file extension dir	Directory indicator
file extension dis	Soundweb firmware file
file extension dmp	Memory dump, screen dump, junk files...
file extension drv	Device Driver
file extension dsp	Dr.Halo graphics display driver
file extension dss	Screensaver file
file extension DS_Store	Macintosh OS X Folder Information
file extension dvd	DOS Device Driver File
file extension ecw	System Dll file
file extension evt	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 flt	OS/2 Warp Filter Device Driver
file extension ftg	Windows Help file
file extension fts	Windows Help index
file extension gadget	Windows sidebar gadget file
file extension grb	MS-DOS Shell Monitor file
file extension grp	Windows Program Group 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 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 extension idx	Index file
file extension idx	Corel QuickFinder index
file extension idx	Microsoft Outlook Express file
file extension ifs	OS/2 installable file system
file extension inf	Autostart CDROM file
file extension inf	Windows installation script
file extension ins	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 lck	Lock file (database access control)
file extension lock	Lock file
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 MDMP	Windows Minidump file
file extension mfl	Microsoft Windows XP System32 WBEM file
file extension mft	NTFS master file table file
file extension mob	Device definition (PEN Windows)
file extension mod	File implementing DOS support for Windows DLL's
file extension mod	Windows kernel module
file extension mos	System Dos62 file
file extension mpa	Palm memo 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 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 nt	Windows NT Startup File
file extension ocx	ActiveX control 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 plt	EPOC software platform file
file extension plt	HP Graphics Language file (plotter)
file extension pol	Windows Policy File
file extension prefpane	Mac OS X System Preference Pane
file extension prf	Windows system file
file extension rtb	NAT proxy servers file
file extension Savedsearch	Spotlight Saved Search
file extension saver	Mac OS X Screen Saver
file extension scc	Visual SourceSafe control file