| Extension | File Description |
| .ADM | System Files |
| .ADML | System Files |
| .ADMX | System Files |
| .AML | System Files |
| .ANI | System Files |
| .ANN | System Files |
| .AOS | System Files |
| .BK2 | System Files |
| .BLF | System Files |
| .BOM | System Files |
| .CAB | System Files |
| .CAT | System Files |
| .CDMP | System Files |
| .CHS | System Files |
| .CHT | System Files |
| .CI | System Files |
| .CNT | System Files |
| .CPI | System Files |
| .CPL | System Files |
| .CPQ | System Files |
| .CPR | System Files |
| .CRASH | System Files |
| .CUR | System Files |
| .DESKLINK | System Files |
| .DIT | System Files |
| .DMP | System Files |
| .DRV | System Files |
| .DSS | System Files |
| .DYC | System Files |
| .EFI | System Files |
| .ETL | System Files |
| .EVT | System Files |
| .EVTX | System Files |
| .FFA | System Files |
| .FPBF | System Files |
| .FTG | System Files |
| .FTS | System Files |
| .GMMP | System Files |
| .GRL | System Files |
| .GRP | System Files |
| .HDMP | System Files |
| .HELP | System Files |
| .HHC | System Files |
| .HHK | System Files |
| .HIV | System Files |
| .HLP | System Files |
| .HPJ | System Files |
| .HSH | System Files |
| .HTT | System Files |
| .ICL | System Files |
| .ICNS | System Files |
| .ICO | System Files |
| .IDX | System Files |
| .IMG3 | System Files |
| .ION | System Files |
| .IPOD | System Files |
| Extension | File Description |
| .ITS | System Files |
| .JPN | System Files |
| .KEXT | System Files |
| .KO | System Files |
| .KOR | System Files |
| .library-ms | System Files |
| .LNK | System Files |
| .LPD | System Files |
| .MANIFEST | System Files |
| .MAPIMAIL | System Files |
| .MDMP | System Files |
| .MI4 | System Files |
| .MLC | System Files |
| .MSC | System Files |
| .MSSTYLES | System Files |
| .MUM | System Files |
| .MYDOCS | System Files |
| .NB0 | System Files |
| .NLS | System Files |
| .NT | System Files |
| .PANIC | System Files |
| .PAT | System Files |
| .PFX | System Files |
| .PIT | System Files |
| .PNF | System Files |
| .POL | System Files |
| .PPD | System Files |
| .PPM | System Files |
| .PREFPANE | System Files |
| .PS2 | System Files |
| .PWL | System Files |
| .QVM | System Files |
| .RC2 | System Files |
| .RCO | System Files |
| .REG | System Files |
| .RMT | System Files |
| .RS | System Files |
| .RUF | System Files |
| .SAVEDSEARC | System Files |
| .SAVER | System Files |
| .SBN | System Files |
| .SCHEMAS | System Files |
| .SEARCHCONN | System Files |
| .SFCACHE | System Files |
| .SHD | System Files |
| .SWP | System Files |
| .SYS | System Files |
| .THEME | System Files |
| .VGA | System Files |
| .VGD | System Files |
| .VXD | System Files |
| .WEBPNP | System Files |
| .WPH | System Files |
| .XRM-MS | System Files |
| .~NT | System Files |
