| .q0 | Japanese Q0 Bitmap Image |
| .q00 | Quicken 2000 |
| .q01 | Quicken 2001 |
| .q06 | QuickTax 2006 |
| .q07 | QuickTax 2007 Tax Return Format |
| .q08 | QuickTax 2008 Tax Return Format |
| .q09 | QuickTax 2009 Tax Return Format |
| .q1 | Winamp Equalizer Preset Format |
| .q1q | LunarCell Adobe Photoshop Plug-in Format |
| .q2 | Winamp Auto-load Preset Format |
| .q2d | Quick3DCover Design Format |
| .q2plug | Quake 2 For Mac Game |
| .q2q | Flexify Adobe Photoshop Plug-in Format |
| .q2renderer | Quake 2 For Mac Renderer Extension |
| .q3c | Quick3DCover Project Format |
| .q3d | Quickdraw 3D Format |
| .q3x | QuickDraw 3D Extension |
| .q4q | Solar Cell Adobe Photoshop Plug-in Format |
| .q5q | SuperBladePro Preset |
| .q5r | Melancholytron Adobe Photoshop Plug-in Format |
| .q7q | India Ink Plug-in Format |
| .q8r | Flood Adobe Photoshop Plug-in Format |
| .q98 | Quicken 98 |
| .q9r | Glitterato Adobe Photoshop Plug-in Format |
| .q9s | Mr. Contrast Adobe Photoshop Plug-in Format |
| .qad | Corel WordPerfect Office Thumbnail |
| .qag | Norton Desktop Quick Access Group |
| .qap | Omnis Quartz Application |
| .qar | QlikView Plug-in Format |
| .qat | Microsoft Office Quick Access Toolbar Info |
| .qb | Diploma Question |
| .qb1 | Quicken Data |
| .qb2005 | QuickBooks 2005 For Mac Backup Format |
| .qb2006 | QuickBooks 2006 For Mac Backup Format |
| .qb2007 | QuickBooks 2007 For Mac Backup Format |
| .qb2008 | Quickbook 2009 For Mac Backup |
| .qb2009 | QuickBooks 2009 For Mac Backup Format |
| .qb2010 | QuickBooks 2010 For Mac Backup Format |
| .qb2011 | QuickBooks 2011 For Mac Backup Format |
| .qb2012 | QuickBooks 2012 For Mac Backup Format |
| .qb2013 | QuickBooks 2013 For Mac Backup |
| .qb2014 | QuickBooks For Mac 2014 Backup |
| .qba | QuickBooks Accountant Review Copy |
| .qbb | QuickBooks Backup Format |
| .qbd | Quicken Keyboard Layout |
| .qbe | Corel Quattro Pro Saved Query |
| .qbi | QuickBooks Image |
| .qbk | QuickTax Backup Format |
| .qbl | Business Lawyer Document |
| .qbm | QuickBooks Portable Company Format |
| .qbmb | QuickBooks Backup Format |
| .qbmd | QuickBooks Backup Format |
| .qbo | QuickBooks Online Bank Statement Format |
| .qbp | QuickBooks Printer |
| .qbquery | MySQL Query Browser Saved SQL Query Command |
| .qbr | Quickbooks Report Template |
| .qbt | QuicBooks Temporary Rebuild |
| .qbw | QuickBooks Company Format |
| .qbx | QuickBooks Accountant Transfer Format |
| .qby | Quickbooks Accountants Import |
| .qc | Quake C Script Format |
| .qc-emod | QuadraComposer Audio |
| .qcd | QuarkXpress Article |
| .qcf | Microsoft QBasic Coordinates |
| .qch | Quicken DOS Data |
| .qci | Massively Parallel Quantum Chemistry Program |
| .qck | Jigsaw 2 Astrological Tool |
| .qcn | Qualcomm QPST Drive Backup |
| .qcow | QEMU Copy-On-Write |
| .qcow2 | QEMU Copy-On-Write |
| .qcp | Qualcomm PureVoice QCELP Recorder And Player Voice Format |
| .qct | QuarkXpress Article Template |
| .qd0 | Omnis Quartz Segment 10 Data |
| .qd1 | Omnis Quartz Segment 1 Data |
| .qd2 | Omnis Quartz Segment 2 Data |
| .qd3 | Omnis Quartz Segment 3 Data |
| .qd3d | QuickDraw 3D Meta |
| .qd4 | Omnis Quartz Segment 4 Data |
| .qd5 | Omnis Quartz Segment 5 Data |
| .qd6 | Omnis Quartz Segment 6 Data |
| .qd7 | Omnis Quartz Segment 7 Data |
| .qd8 | Omnis Quartz Segment 8 Data |
| .qd9 | Omnis Quartz Segment 9 Data |
| .qda | Quadruple D Archive Format |
| .qdat | Quicktime Installer Cache |
| .qdb | Quicken Backup Format |
| .qdc | Quick Devis Database |
| .qdf | Quicken Financial Data Format |
| .qdf-backup | Quicken Financial Data Backup Format |
| .qdfm | Quicken For Mac Data Format |
| .qdfx | Quicken Essentials For Mac Financial Data Exchange Format |
| .qdi | Quicken Dictionary Data |
| .qdk | QEMM Startups Backup |
| .qdl | QDL Source Code Format |
| .qdlx | Quicken For Mac Data |
| .qdm | FsQCA Data |
| .qdp | MPQDraft Plugin Format |
| .qdr | Q-Dir Configuration |
| .qds | Windows Directory Query Format |
| .qdt | QuarkXpress Auxiliary Dictionary Format |
| .qdv | Random Dot QDV Bitmap Image |
| .qe4 | Kingpin Life Of Crime Settings |
| .qed | Memory-Map Navigator Map |
| .qef | Microsoft Excel Query |
| .qel | Quicken Electronic Library Format |
| .qem | ExpensAble Report |
| .qes | Askiadesign Questionnaire |
| .qex | ExpensAble Data |
| .qf | Nokia (Ovi) Maps Version Format |
| .qfc | QuickFileCollection Archive |
| .qfd | Quicken Data |
| .qfi | Quicken 2002 Data |
| .qfilter | Mac OS X ColorSync Filter |
| .qfl | Family Lawyer Document |
| .qfn | Apple QuickTime Font |
| .qfp | Quicken Financial Planner Add-on |
| .qfs | Need For Speed Tracks Trk000 |
| .qfx | Quicken Financial Exchange Format |
| .qgis | Quantum GIS Project |
| .qgs | Quantum GIS Project |
| .qhc | Qt Help Collection |
| .qhcp | Qt Help Collection Project |
| .qhf | QIP Saved History |
| .qhp | Qt Help Project |
| .qht | Apple QuickTime HTML |
| .qhtm | Apple QuickTime HTML |
| .qic | Microsoft Windows 95/98 Backup Format |
| .qid | Quicken |
| .qif | Quicken Interchange Format |
| .qin | CARE-S InfoWorks Inflow |
| .qip | QIP Infium Account |
| .qit | Backdoor.QIT Trojan Horse Format |
| .qix | Quicken DOS Data |
| .qkex | QuicKeys Mac Extension |
| .qkpt | KaleidaGraph |
| .qkr | Quickr Attachment Link |
| .qkt | Microsoft Works |
| .qky | Linux Quirky Kernel Format |
| .ql | Qedit |
| .qlb | Microsoft QuickBasic Library |
| .qlc | Adobe PostScript Help |
| .qld | MassLynx Quantation Data |
| .qlgenerator | Apple Quicklook Plug-in Format |
| .qli | Statler Stitcher |
| .qm | Qt Compiled Translation Source Format |
| .qm3 | Articulate Quizmaker Compressed |
| .qm4 | Qmail Options Or Services |
| .qma | Qedit |
| .qmb | Quick Menu Builder Saved |
| .qmbl | LabQuest Results |
| .qmd | Quicken Win Version 5/6 Backup |
| .qme | Quicken Win Version 3 |
| .qmethod | AB SCIEX MultiQuant Quantitation Method |
| .qmf | IBM Lotus Approach Database Query |
| .qmg | Samsung Theme Picture Image File - Qmage File Format |
| .qmk | YanCEyDesktop Bookmark Format |
| .qml | Quicken DOS Data |
| .qmp | SeeYou Raster Map |
| .qmsb | Questionmark Secure |
| .qmt | Quicken Memory List |
| .qmtf | Intuit Quicken Data |
| .qnt | Chromeleon Quantification Method |
| .qnx | Quicken Index |
| .qob | QuickBooks 2010 Pro |
| .qot | Sierra Print Artist Quotes |
| .qp03 | Qpress Compressed Archive |
| .qp1 | QuickPar Cache |
| .qp2 | QuickPar Cache |
| .qpa | Quicktime Player Addition |
| .qpb | Quicken Payroll Format |
| .qpc | KaleidaGraph Plot |
| .qpct | KaleidaGraph Plot |
| .qpd | Quicken QuickPay Windows 3.0 Add-on |
| .qpf | Quartus II Project Format |
| .qph | Intuit Quicken Price History Format |
| .qpi | Quicken Win Version 3 |
| .qpj | Quantum GIS Project |
| .qpl | KaleidaGraph Layout |
| .qpm | Quick Pallet Maker Input Data Format |
| .qpr | FoxPro Database Query |
| .qproj | FreeQ IDE Project |
| .qps | Timeasure |
| .qpt | QuarkXPress Project Template Format |
| .qpw | Corel Quattro Pro Spreadsheet Format |
| .qpx | FoxPro Compiled Executable QBE Query Format |
| BLU Archive | |
| .qqq | TotalFix Fixed AVI |
| .qr2 | Delphi Database Quick Report |
| .qrc | Qt Resource Collection Format |
| .qrf | QR Form |
| .qrm | Qworum Message Format |
| .qrp | Dr. Hardware Format |
| .qrs | Corel WordPerfect Equation Editor Support |
| .qrt | Qrt Ray-Tracer Ray-traced Bitmap Image |
| .qry | Database Query Format |
| .qsc | Kaleidagraph Script |
| .qsd | Quicken Data Format |
| .qsession | AB SCIEX MultiQuant Quantitation Session |
| .qsf | Qualtrics Survey Format |
| .qsk | Quintessential Player Skin |
| .qsp | QSetup Installation Suite |
| .qsr | CARE-S InfoWorks Water Quality Simulation Results |
| .qss | Nokia Qt Style Sheet Format |
| .qst | Ami Pro Quickstart Tutorial Image |
| .qsty | KaleidaGraph Style |
| .qsu | Zelda Classic Quest |
| .qsv | Jigs@w Saved Puzzle State |
| .qsx | QuickSurf |
| .qt | Apple QuickTime Movie Clip |
| .qtb | ExamView QuickTake Question Bank |
| .qtc | Apple QuickTime Support |
| .qtch | Apple QuickTime Cached Format |
| .qtf | Qtracker Filter |
| .qti | Apple QuickTime Image Format |
| .qtif | Apple QuickTime Image Format |
| .qtindex | Adobe QTIndex Format |
| .qtk | Apple QuickTake Picture Image |
| .qtl | YUV SECAM Or PAL Image |
| .qtm | Apple QuickTime Movie Format |
| .qtp | Apple QuickTime Preferences Format |
| .qtr | Apple QuickTime Extension Resource Format |
| .qts | QuickTime System |
| .qtv | QuickTime Virtual Reality |
| .qtvr | QuickTime VR |
| .qtx | Quicken Data Format |
| .qtxs | Apple QuickTime |
| .qtz | QuaSZ Texture Format |
| .qu2 | GPS2WorldWind Database |
| .qua | Avira AntiVir Format |
| .quad | QUAD Compressed Archive |
| .qualsoftcode | Speedy Browser Code Archive |
| .qud | QuarkXpress Auxiliary Dictionary |
| .que | CuteFTP Queue |
| .questtemplate | Starbound Quest Template |
| .qui | Orgadata LogiKal |
| .QuickBooksAutoDataRecovery | QuickBooks Auto Recovery |
| .quickenbackup | Quicken Essentials For Mac Financial Data Backup Format |
| .quickendata | Quicken Essentials For Mac Financial Data Format |
| .quicktimecomponents | Mac OS X System |
| .quiz | Quizmaker 09 To 13 Quiz Format |
| .quiztemplate | Articulate Studio Quizmaker |
| .quo | ESignal Qoute |
| .quox | Quobject Format |
| .qup | QuickTime Update Package |
| .qut | IBM Voice Type Languages Vocable |
| .qvd | Quaanta Interactive Media Desktop Format |
| .qvm | Quake Format |
| .qvo | QlikView Table |
| .qvp | ViewletBuilder Project Format |
| .qvpp | QlikView Extension Properties Page Format |
| .qvt | Quantum Streaming Video Stream Url Format |
| .qvw | QlikView Document Format |
| .qv~ | ViewletBuilder Project Backup Format |
| .qw5 | Quicken Win Version 5 |
| .qwb | Microsoft Money Quotes WriteBack Import |
| .qwd | QuakeWorld Demo Format |
| .qwp | Quiptics Puzzle Format |
| .qwq | OpenQwaq Auto-Launch Format |
| .qwt | QuarkXpress Web Document Template |
| .qx | Quexal Source Code |
| .qxb | QuarkXpress Multiple Document Publication Book File Format |
| .qxd | QuarkXPress Document Format |
| .qxf | Quicken Essentials For Mac Financial Data Exchange Format |
| .qxl | QuarkXPress Element Library Format |
| .qxml | Question Master Administration Tool Output |
| .qxp | QuarkXpress Project Format |
| .qxt | QuarkXPress Template Format |
| .qz | Create A Quiz Data |
| .qze | QZip Encrypted |
| .qzs | QuizPro Data |
File extensions are not normally displayed to users. To change this, go to Control Panel, select Appearance and Personalization and Folder Options. Next, select the View and find the option "Hide extensions for known file types". The option should be deselected (cleared) and confirmed with OK.
