System Files
The System Files category includes files related to Mac, Windows, and Linux operating systems. Some examples include system libraries, icons, themes, and device drivers. Files output by the system are also included in this category.
Common system file extensions include .DLL, .DRV, .SYS, and .CAB.
| Extension | File Type | Popularity |
|---|---|---|
| .LOCKFILE | Mac OS X PLIST Lock File | 4.5 |
| .REG | Registry File | 4.4 |
| .AML | ACPI Machine Language File | 4.4 |
| .ADMX | Group Policy Administrative Template File | 4.4 |
| .VGA | VGA Display Driver | 4.3 |
| .SHSH2 | iOS SHSH Blob | 4.3 |
| .CUR | Windows Cursor | 4.3 |
| .REGTRANS-MS | Registry Transaction Log File | 4.3 |
| .RMT | Router Firmware File | 4.3 |
| .ANI | Windows Animated Cursor | 4.3 |
| .SEARCHCONNECTOR-MS | Windows Search Connector File | 4.3 |
| .CLB | COM+ Catalog File | 4.3 |
| .ICONPACKAGE | IconPackager Theme File | 4.3 |
| .HTT | Hypertext Template | 4.3 |
| .ICNS | macOS Icon Resource | 4.3 |
| .DLL | Dynamic Link Library | 4.3 |
| .WDGT | Dashboard Widget | 4.3 |
| .NT | Windows NT Startup File | 4.3 |
| .DESKTHEMEPACK | Windows 8 Desktop Theme Pack File | 4.2 |
| .INF_LOC | Windows Driver Information Cache File | 4.2 |
| .HVE | Windows Registry Hive File | 4.2 |
| .DMP | Windows Memory Dump | 4.2 |
| .PK2 | Silkroad Online Game Data File | 4.2 |
| .LNK | Windows Shortcut | 4.2 |
| .DVD | DOS Device Driver | 4.2 |
| .VX_ | Compressed Virtual Device Driver File | 4.2 |
| .THEME | Microsoft Plus! Desktop Theme | 4.2 |
| .ITEMDATA-MS | Windows 8 Start Screen Item Data File | 4.2 |
| .QVM | Q Virtual Machine | 4.2 |
| .RC1 | Samsung Mobile Device Firmware File | 4.2 |
| .MDMP | Windows Minidump | 4.2 |
| .EBD | Windows EBD System File | 4.1 |
| .FTF | FlashTool Firmware File | 4.1 |
| .DESKLINK | Desktop Shortcut | 4.1 |
| .LIBRARY-MS | Windows Library Description File | 4.1 |
| .SYS | Windows System File | 4.1 |
| .NFO | System Information File | 4.1 |
| .73U | TI-73 Explorer Operating System File | 4.1 |
| .HIV | Windows Registry Hive File | 4.1 |
| .SFCACHE | ReadyBoost Cache File | 4.1 |
| .PROP | Android Build Properties File | 4.1 |
| .ASEC | Android Secure Application File | 4.1 |
| .ICO | Icon File | 4.1 |
| .ION | File Description File | 4.1 |
| .FIRM | Boot9Strap 3DS Firmware File | 4.1 |
| .PCK | System Center Configuration Manager Package File | 4.1 |
| .H1S | Windows Assistance Platform Help File | 4.1 |
| .ELF | Executable and Linkable Format File | 4.1 |
| .MANIFEST | Windows Application Manifest File | 4.0 |
| .000 | Indexing Service Data File | 4.0 |
| .MUI | Multilingual User Interface File | 4.0 |
| .SCR | Windows Screensaver | 4.0 |
| .ETL | Microsoft Event Trace Log File | 4.0 |
| .SERVICE | Systemd Service Unit File | 4.0 |
| .FFX | Microsoft Find Fast Index | 4.0 |
| .CGZ | Linux Drivers Archive | 4.0 |
| .CI | Windows Content Indexer Catalog File | 4.0 |
| .PWL | Windows Password List | 4.0 |
| .BIN | Router Firmware File | 4.0 |
| .MENU | macOS Menu Extra | 4.0 |
| .NLT | Windows Transliteration File | 4.0 |
| .TIMER | Systemd Unit Configuration File | 4.0 |
| .ZONE.IDENTIFIER | Windows Zone Identifier File | 4.0 |
| .EDJ | Enlightenment Theme File | 4.0 |
| .MOD | GRUB Module | 4.0 |
| .PREFPANE | Mac OS X System Preference Pane | 4.0 |
| .MAPIMAIL | Send To Mail Recipient | 4.0 |
| .DAT | Windows Registry Hive File | 4.0 |
| .MSC | Microsoft Management Console Snap-in Control File | 4.0 |
| .BASH_HISTORY | Bash History File | 4.0 |
| .ADM | Administrative Template File | 4.0 |
| .CM0013 | Samsung Smart TV Index File | 4.0 |
| .CAB | Windows Cabinet File | 3.9 |
| .EFI | Extensible Firmware Interface File | 3.9 |
| .FX | ReadyBoot Trace File | 3.9 |
| .WDF | Windows Driver Foundation File | 3.9 |
| .MLC | Microsoft Language Interface Pack | 3.9 |
| .LFS | Samsung Phone params.lfs File | 3.9 |
| .MSSTYLES | Windows XP Style | 3.9 |
| .FOTA | Firmware Over-the-Air File | 3.9 |
| .LOG1 | Windows Registry Hive Log File | 3.9 |
| .PNF | Precompiled INF File | 3.9 |
| .SDB | Custom Application Compatibility Database | 3.9 |
| .PAT | DiskStation Manager Installation File | 3.8 |
| .SYS | Motorola Driver File | 3.8 |
| .PIT | Samsung Phone Firmware File | 3.8 |
| .BASH_PROFILE | Bash Interactive Login Shell File | 3.8 |
| .C32 | Syslinux COM32 Module | 3.8 |
| .MOBILECONFIG | Apple Mobile Configuration File | 3.8 |
| .TRX_DLL | Windows Startup File | 3.8 |
| .DRV | Device Driver | 3.8 |
| .MTZ | MIUI Theme | 3.8 |
| .MBR | Master Boot Record File | 3.8 |
| .HHK | HTML Help Index | 3.8 |
| .WEBPNP | Web Point and Print File | 3.8 |
| .SBN | Cisco IP Phone Firmware File | 3.8 |
| .GROUP | Windows Contacts Group File | 3.8 |
| .0 | Shared Library Link File | 3.8 |
| .MSP | Windows Installer Patch | 3.8 |
| .208 | ASUS Notebook BIOS 208 Update File | 3.8 |
| .BCD | Windows Boot Configuration Data File | 3.8 |
| .BASHRC | Bash Non-Interactive Login Shell File | 3.8 |
| .DIT | Active Directory Information Tree File | 3.8 |
| .INS | Internet Naming Service File | 3.8 |
| .3FS | Puppy Linux Save State File | 3.8 |
| .IMG3 | iPhone IMG3 File | 3.8 |
| .DEV | Windows Device Driver File | 3.8 |
| .MUI_CCCD5AE0 | Hid User Library | 3.8 |
| .IOPLIST | Mac OS X IOPLIST File | 3.8 |
| .PDR | Windows Port Driver | 3.8 |
| .PLASMOID | Plasma Widget | 3.8 |
| .PRO | TurboIntegrator Process Definition File | 3.8 |
| .DTHUMB | Android Data Thumbnail | 3.7 |
| .DIAGCAB | Troubleshooting Pack Cabinet File | 3.7 |
| .HDMP | Windows Heap Dump | 3.7 |
| .CPL | Windows Control Panel Item | 3.7 |
| .MBN | Multi Boot Image | 3.7 |
| .DRPM | Delta RPM File | 3.7 |
| .POL | Windows Policy File | 3.7 |
| .CAT | Windows Catalog File | 3.7 |
| .AOS | ARCHOS PCtablet Firmware File | 3.7 |
| .SHD | Windows Print Job Shadow File | 3.7 |
| .NB0 | Device Boot Loader Image | 3.7 |
| .PPD | PostScript Printer Description File | 3.7 |
| .SDT | Siemens Desktop Theme File | 3.7 |
| .AX | DirectShow Filter | 3.7 |
| .CANNEDSEARCH | Apple Predefined Search | 3.7 |
| .CHS | Windows Chinese Noise-Word List File | 3.7 |
| .BIO | BIOS File | 3.7 |
| .VXD | Virtual Device Driver | 3.7 |
| .SAVEDSEARCH | Spotlight Saved Search | 3.7 |
| .1 | Unix Section 1 Manual Page | 3.7 |
| .NLS | Microsoft National Language Support File | 3.6 |
| .JOB | Windows Task Scheduler Job File | 3.6 |
| .CNT | Help Contents File | 3.6 |
| .WPX | Printer Description File | 3.6 |
| .SBF | Android System File | 3.6 |
| .8CU | TI-84 Plus C Operating System File | 3.6 |
| .ADML | Group Policy Language-Specific Administrative Template | 3.6 |
| .KEXT | Mac OS X Kernel Extension | 3.6 |
| .FPBF | Mac OS X Burn Folder | 3.6 |
| .CM0012 | Configuration Management File | 3.6 |
| .HLP | Windows Help File | 3.6 |
| .LST | GRUB Boot List File | 3.6 |
| .IDX | Index File | 3.6 |
| .8XU | TI-83 and TI-84 Plus Operating System File | 3.6 |
| .PRF | Windows System File | 3.5 |
| .CRASH | Mac OS X Crash Log File | 3.5 |
| .CONFIGPROFILE | Apple Configuration Profile | 3.5 |
| .SQM | Service Quality Monitoring File | 3.5 |
| .CHG | Windows Net Logon File | 3.5 |
| .SCHEMAS | GConf Schema Definition File | 3.5 |
| .DFU | iOS DFU File | 3.5 |
| .PANIC | Kernel Panic File | 3.5 |
| .IME | Windows Input Method Editor File | 3.5 |
| .4 | Unix Section 4 Manual Page | 3.5 |
| .LEX | Spelling Dictionary File | 3.5 |
| .TDZ | Drobo Firmware File | 3.5 |
| .WLU | Windows Legacy Update | 3.5 |
| .KS | Kickstart File | 3.5 |
| .WER | Windows Error Report | 3.5 |
| .CPQ | Compaq OEM Disc Configuration File | 3.5 |
| .GRP | Windows Program Manager Group | 3.5 |
| .SWP | Swap File | 3.5 |
| .SHSH | iPhone/iPod Touch SHSH Blob File | 3.5 |
| .386 | Windows Virtual Device Driver | 3.5 |
| .2FS | Puppy Linux Save State File | 3.5 |
| .ODEX | Optimized Dalvik Executable | 3.5 |
| .PROFILE | Bash Shell Profile | 3.5 |
| .LOG2 | Windows Registry Hive Log 2 File | 3.4 |
| .BLF | CLFS Base Log File | 3.4 |
| .SAVER | Mac OS X Screen Saver | 3.4 |
| .PS2 | Microsoft Search Catalog Index File | 3.4 |
| .NTFS | NTFS Partition File | 3.4 |
| .HCD | Samsung Android Firmware File | 3.4 |
| .HHC | HTML Help Table of Contents | 3.4 |
| .ADV | Audio Driver File | 3.4 |
| .DATABASE_UUID | Android Stale Thumbnails Identifier | 3.4 |
| .KO | Linux Kernel Module File | 3.4 |
| .CHK | Netgear Router Firmware File | 3.3 |
| .DIMAX | DiMAX Firmware Image File | 3.3 |
| .IM4P | IMG4 Payload File | 3.3 |
| .IPOD | Rockbox Firmware File | 3.3 |
| .PROVISIONPROFILE | Apple Provision Profile | 3.3 |
| .THA | Windows Thai Noise-Words List File | 3.3 |
| .PRINTEREXPORT | Windows Printer Migration File | 3.3 |
| .METADATA_NEVER_INDEX | Spotlight Never Index File | 3.3 |
| .ICL | Windows Icon Library File | 3.3 |
| .FLG | Puppy Linux Partition Flag File | 3.3 |
| .PFX | PKCS #12 Certificate File | 3.3 |
| .BMK | Windows Help Bookmarks | 3.3 |
| .CHT | Windows Chinese Traditional Noise-Word List File | 3.3 |
| .CPI | Codepage Information File | 3.3 |
| .ATAHD | ATA Hard Drive Flag File | 3.3 |
| .BOM | Mac OS X Bill of Materials File | 3.3 |
| .NBH | ROM Update Utility Image File | 3.3 |
| .MSSTYLE | Windows XP Unsigned Style | 3.3 |
| .FFO | Find Fast Document Properties Cache | 3.3 |
| .MI4 | Audio Player Firmware File | 3.3 |
| .RUF | Samsung DVD and Blu-ray Player Firmware File | 3.2 |
| .PID | Creative Driver File | 3.2 |
| .XRM-MS | Microsoft Security Certificate | 3.2 |
| .PRT | Printer Driver File | 3.2 |
| .STR | Windows Screensaver File | 3.2 |
| .EVTX | Windows 7 Event Log File | 3.2 |
| .CUSTOMDESTINATIONS-MS | Windows Jump List File | 3.2 |
| .CAP | ASUS BIOS Update File | 3.2 |
| .MYDOCS | Send To My Documents | 3.2 |
| .BK2 | Windows Indexing Service Data File | 3.1 |
| .SPL | Windows Print Spool File | 3.1 |
| .MUM | Windows Vista Update Package | 3.1 |
| .CPR | Windows Phone Display Settings File | 3.1 |
| .PS1 | Microsoft Indexing Service Data File | 3.1 |
| .THUMBNAILS | Android Thumbnails Folder | 3.0 |
| .RFW | Rockchip Firmware File | 3.0 |
| .TBRES | Microsoft Store TokenBroker Cache File | 3.0 |
| .KC | macOS Kernel Extension Boot File | 3.0 |
| .SPRX | Signed PlayStation Relocatable Executable | 3.0 |
| .SCF | Windows Explorer Command | 3.0 |
| .HPJ | Help Project File | 3.0 |
| .SIN | Sony Xperia Firmware File | 3.0 |
| .CMO | ASUS BIOS File | 3.0 |
| .ME | Puppy Linux Partition Flag File | 3.0 |
| .HSH | Windows Catalog Search Index File | 3.0 |
| .WGZ | S60 Web Runtime Widget Package | 3.0 |
| .OZIP | OPPO Smartphone Firmware Update | 3.0 |
| .BK1 | Windows Indexing Service File | 3.0 |
| .DLX | Renamed DLL File | 3.0 |
| .FTR | IRIX File Type Rules File | 3.0 |
| .EVT | Windows Event Viewer Log File | 3.0 |
| .KDZ | LG Mobile Device Firmware | 3.0 |
| .UTV | SmartCast TV Firmware Update | 3.0 |
| .EFIRES | EFI Image File | 3.0 |
| .IFW | INTUS Firmware File | 3.0 |
| .MUN | Windows System Resource Archive | 3.0 |
| .B84 | TI-84 Plus CE Bundle Image | 3.0 |
| .DIAGPKG | Troubleshooting Pack File | 3.0 |
| .UCE | Windows UCE System File | 3.0 |
| .GMMP | WCS Gamut Map Model Profile | 3.0 |
| .0 | Android CA Digital Certificate | 3.0 |
| .ESCOPY | ES File Explorer File Manager Temporary File | 3.0 |
| .MEM | Parallels Desktop Memory Dump File | 3.0 |
| .XFB | Xserve RAID Firmware Binary File | 3.0 |
| .NETWORKCONNECT | Apple Network Connect Document | 3.0 |
| .SO.0 | Unix Shared Library File | 2.9 |
| .SCAP | EFI Firmware File | 2.9 |
| .GRL | Windows Update Status File | 2.9 |
| .DSS | DCC Active Designer File | 2.8 |
| .FL1 | Lenovo BIOS Update File | 2.8 |
| .FFA | Find Fast Status File | 2.8 |
| .LPD | LPD Daemon Print Permissions File | 2.8 |
| .AUTOMATICDESTINATIONS-MS | Windows Jump List File | 2.8 |
| .KBD | Keyboard Layout Script | 2.8 |
| .DEVICEMETADATA-MS | Device Metadata Package | 2.8 |
| .TRASHES | macOS USB Flash Drive Trash Folder | 2.8 |
| .KEY | Android Passcode File | 2.7 |
| .PPM | Post Programmable Memory File | 2.7 |
| .RC2 | Samsung Mobile Device Firmware File | 2.7 |
| .VDEX | Validated Dalvik Executable File | 2.7 |
| .LM | Language Model File | 2.7 |
| .FTS | Full Text Search | 2.7 |
| .DOCK | Mac OS X Dock Extra | 2.6 |
| .JETKEY | iOS Support Jet File | 2.6 |
| .IDI | EVA Controller Event Log | 2.6 |
| .SB | Slax Bundle | 2.6 |
| .VGD | Generic CADD VGA Driver | 2.6 |
| .BUD | Binary Printer Description File | 2.6 |
| .KWI | Toyota Entune Update File | 2.5 |
| .IPTHEME | IconPackager Raw Theme File | 2.5 |
| .DIAGCFG | Troubleshooting Pack Configuration File | 2.5 |
| .RCO | PlayStation Portable Resource File | 2.5 |
| .DIC | Windows 10 Custom Spelling Dictionary | 2.5 |
| .WPH | Phoenix BIOS File | 2.5 |
| .2 | Unix Section 2 Manual Page | 2.5 |
| .LPD | Lookout Protocol Driver File | 2.5 |
| .6 | Unix Section 6 Manual Page | 2.5 |
| .5 | Unix Section 5 Manual Page | 2.5 |
| .PUSH_DEVICEID | Android Device Identification File | 2.5 |
| .QKY | Quirky Kernel | 2.4 |
| .RS | Windows Rating System File | 2.4 |
| .DYC | Xerox Printer Driver Configuration File | 2.4 |
| .JPN | Windows Japanese Noise-Word List File | 2.4 |
| .KL | Android Key Layout File | 2.3 |
| .3 | Unix Section 3 Manual Page | 2.3 |
| .LOCALIZED | macOS Directory Localization File | 2.3 |
| .FID | Microsoft Catalog Indexing Service File | 2.3 |
| .TA | Sony Firmware File | 2.3 |
| .INTERNETCONNECT | Apple Internet Connect Document | 2.3 |
| .SPX | System Profiler XML Report | 2.3 |
| .RCV | BIOS Recovery File | 2.0 |
| .TCO2 | TI-Nspire CX II Operating System File | 2.0 |
| .EMERALD | Emerald Theme | 2.0 |
| .FFL | Find Fast Document List | 2.0 |
| .MMV | Magnex Firmware File | 2.0 |
| .TRASHINFO | Linux Trash Metadata File | 2.0 |
| .CDMP | WCS Device Model Profile | 2.0 |
| .89U | TI-89 Titanium Operating System File | 2.0 |
| .ROKU | Roku TV Firmware Update | 2.0 |
| .ITS | Internet Document Set | 2.0 |
| .7 | Unix Section 7 Manual Page | 2.0 |
| .B83 | TI-83 Premium CE Bundle Image | 2.0 |
| .DUB | Windows Spelling Dictionary Identifier | 2.0 |
| .BBFW | Apple Baseband Firmware Update | 2.0 |
| .KOR | Windows Korean Noise-Words List File | 2.0 |
| .IUS | InfoTMIC Firmware Update File | 2.0 |
| .FTG | Full Text Group | 2.0 |
| .ANN | Windows Help Annotations | 1.8 |
| .REGLNK | Registry Editor Shortcut File | 1.8 |
| .8 | Unix Section 8 Manual Page | 1.8 |
| .HELP | Mac OS X Help Book | 1.6 |
| .DIFFBASE | Windows Diagnostics Tracking Diffbase File | 1.5 |
| .RVP | Sharp Blu-ray Player Firmware File | 1.0 |
| .SELF | Signed Executable and Linkable Format | 1.0 |
| .SEFW | Secure Element Firmware | 1.0 |