| Extension | File Description |
| .IC9 | Uncommon Files |
| .ICA | Settings Files |
| .ICAL | Misc Files |
| .ICALENDAR | Misc Files |
| .ICB | Raster Image Files |
| .ICC | Settings Files |
| .ICCP | Uncommon Files |
| .ICD | Executable Files |
| .ICDX | Uncommon Files |
| .ICE | Compressed Files |
| .ICEICEBABY | Uncommon Files |
| .ICF | Uncommon Files |
| .ICG | Uncommon Files |
| .ICH | Uncommon Files |
| .ICI | Uncommon Files |
| .ICJ | Uncommon Files |
| .ICK | Uncommon Files |
| .ICL | System Files |
| .ICM | Settings Files |
| .ICMP | Uncommon Files |
| .ICMS | Uncommon Files |
| .ICN | Raster Image Files |
| .ICNS | System Files |
| .ICO | System Files |
| .icon | Raster Image Files |
| .ICON2 | Uncommon Files |
| .ICONES | Uncommon Files |
| .ICONS | Uncommon Files |
| .ICONS1 | Uncommon Files |
| .ICONS2 | Uncommon Files |
| .ICP | Uncommon Files |
| .ICPR | Raster Image Files |
| .ICQ | Uncommon Files |
| .ICR | Uncommon Files |
| .ICS | Misc Files |
| .ICT | Uncommon Files |
| .ICTX | Uncommon Files |
| .ICU | Uncommon Files |
| .ICV | Uncommon Files |
| .ICW | Uncommon Files |
| .ICX | Uncommon Files |
| .ICY | Uncommon Files |
| .ICZ | Uncommon Files |
| .IC_ | Uncommon Files |
| .ID | Misc Files |
| .ID0 | Uncommon Files |
| .ID1 | Uncommon Files |
| .ID2 | Uncommon Files |
| .ID3 | Uncommon Files |
| .ID4 | Uncommon Files |
| .ID5 | Uncommon Files |
| .ID6 | Uncommon Files |
| .ID7 | Uncommon Files |
| .ID8 | Uncommon Files |
| .ID9 | Uncommon Files |
| .IDA | Uncommon Files |
| .IDAPI | Uncommon Files |
| .IDB | Database Files |
| .IDC | Web Files |
| .IDD | Uncommon Files |
| .IDE | CAD Files |
| .IDEA | Vector Image Files |
| .IDEAS | Uncommon Files |
| .IDEMO | Uncommon Files |
| .IDENTIFIER | Uncommon Files |
| .IDF | Settings Files |
| .IDG | Uncommon Files |
| .IDH | Uncommon Files |
| .IDI | Uncommon Files |
| .IDIF | Uncommon Files |
| .IDJ | Uncommon Files |
| .IDK | Uncommon Files |
| .IDL | Developer Files |
| .IDLK | Misc Files |
| .IDM | Uncommon Files |
| Extension | File Description |
| .IDMEF | Uncommon Files |
| .IDN | Uncommon Files |
| .IDO | Uncommon Files |
| .IDOL | Uncommon Files |
| .IDP | Uncommon Files |
| .IDQ | Uncommon Files |
| .IDR | Uncommon Files |
| .IDS | Uncommon Files |
| .IDSP | Uncommon Files |
| .IDT | Developer Files |
| .IDU | Uncommon Files |
| .IDV | CAD Files |
| .IDW | CAD Files |
| .IDWORDCOUN | Uncommon Files |
| .IDX | System Files |
| .IDY | Uncommon Files |
| .IDZ | Uncommon Files |
| .ID_ | Uncommon Files |
| .IE | Uncommon Files |
| .IE0 | Uncommon Files |
| .IE1 | Uncommon Files |
| .IE1-3 | Uncommon Files |
| .IE2 | Uncommon Files |
| .IE3 | Uncommon Files |
| .IE4 | Uncommon Files |
| .IE5 | Uncommon Files |
| .IE6 | Uncommon Files |
| .IE7 | Uncommon Files |
| .IE8 | Uncommon Files |
| .IE9 | Uncommon Files |
| .IEA | Uncommon Files |
| .IEB | Uncommon Files |
| .IEC | Uncommon Files |
| .IED | Uncommon Files |
| .IEE | Uncommon Files |
| .IEE-695 | Uncommon Files |
| .IEF | Uncommon Files |
| .IEG | Uncommon Files |
| .IEH | Uncommon Files |
| .IEI | Uncommon Files |
| .IEJ | Uncommon Files |
| .IEK | Uncommon Files |
| .IEL | Uncommon Files |
| .IEM | Uncommon Files |
| .IEN | Uncommon Files |
| .IEO | Uncommon Files |
| .IEP | Uncommon Files |
| .IEPK | Uncommon Files |
| .IEQ | Uncommon Files |
| .IER | Uncommon Files |
| .IES | Data Files |
| .IET | Uncommon Files |
| .IEU | Uncommon Files |
| .IEV | Uncommon Files |
| .IEW | Uncommon Files |
| .IEX | Uncommon Files |
| .IEY | Uncommon Files |
| .IEZ | Uncommon Files |
| .IF0 | Uncommon Files |
| .IF1 | Uncommon Files |
| .IF2 | Uncommon Files |
| .IF3 | Uncommon Files |
| .IF4 | Uncommon Files |
| .IF5 | Uncommon Files |
| .IF6 | Uncommon Files |
| .IF7 | Uncommon Files |
| .IF8 | Uncommon Files |
| .IF9 | Uncommon Files |
| .IFA | Uncommon Files |
| .IFB | Uncommon Files |
| .IFC | 3D Image Files |
| .IFD | Page Layout Files |
| .IFE | Uncommon Files |
| .IFF | Audio Files |
| .IFG | Uncommon Files |
