Reserved file and URI scheme names

You can use URI associations to automatically launch your app when another app launches a specific URI scheme. But there are some URI associations that you can’t use because they are reserved. If your app registers for a reserved association, that registration will be ignored. This topic lists the reserved file and URI scheme names that are not available to your app.

Reserved file types

There are two types of reserved file types: file types reserved for built-in apps and file types reserved for the operating system. When a file type reserved for a built-in app is launched, only the built-in app will launch. Any attempt to register your app with that file type is ignored. Similarly, any attempt to register your app with a file type reserved for the operating system also will be ignored.

File types reserved for built-in apps

.aac.icon.pem.wdp
.aetx.jpeg.png.wmv
.asf.jxr.pptm.xap
.bmp.m4a.pptx.xht
.cer.m4r.qcp.xhtml
.dotm.m4v.rtf.xltm
.dotx.mov.tif.xltx
.gif.mp3.tiff.xml
.hdp.mp4.txt.xsl
.htm.one.url.zip
.html.onetoc2.vcf
.ico.p7b.wav
 

File types reserved for the operating system

The following file types are reserved for the operating system

.accountpicture-msits.ops.url
.ade.jar.pcd.vb
.adp.js.pif.vbe
.app.jse.pl.vbp
.appx.ksh.plg.vbs
.application.lnk.plsc.vhd
.appref-ms.mad.prf.vhdx
.asp.maf.prg.vsmacros
.bas.mag.printerexport.vsw
.bat.mam.provxml.webpnp
.cab.maq.ps1.ws
.chm.mar.ps1xml.wsc
.cmd.mas.ps2.wsf
.cnt.mat.ps2xml.wsh
.com.mau.psc1.xaml
.cpf.mav.psc2.xdp
.cpl.maw.psm1.xip
.crd.mcf.pst.xnk
.crds.mda.pvw
.crt.mdb.py
.csh.mde.pyc
.der.mdt.pyo
.dll.mdw.rb
.drv.mdz.rbw
.exe.msc.rdp
.fxp.msh.reg
.fon.msh1.rgu
.gadget.msh1xml.scf
.grp.msh2.scr
.hlp.msh2xml.shb
.hme.mshxml.shs
.hpj.msi.sys
.hta.msp.theme
.inf.mst.tmp
.ins.msu.tsk
.isp.ocx.ttf

Reserved URI scheme names

application.manifestinternetshortcutms-settings:network-mobilehotspotshbfile
application.referencejavascriptms-settings:network-proxyshcmdfile
batfilejscriptms-settings:network-wifishsfile
bingjsefilems-settings:nfctransactionssmb
blobldapms-settings:notificationsstickynotes
calltolnkfilems-settings:personalizationsysfile
cerfilemailtoms-settings:privacy-calendartel
chm.filecmdfilecomfilemapsms-settings:privacy-contactstelnet
cplfilemicrosoft.powershellscript.1ms-settings:privacy-customdevicestn3270
dllfilems-accountpictureproviderms-settings:privacy-feedbackttffile
drvfilems-appdatams-settings:privacy-locationunknown
dtmfms-appxms-settings:privacy-messagingusertileprovider
exefilems-autoplayms-settings:privacy-microphonevbefile
explorer.assocactionid.burnselectionms-excelms-settings:privacy-speechtypingvbscript
explorer.assocactionid.closesessionmsi.packagems-settings:privacy-webcamvbsfile
explorer.assocactionid.erasediscmsi.patchms-settings:proximitywallet
explorer.assocactionid.zipselectionms-powerpointms-settings:regionlanguagewindows.gadget
explorer.assocprotocol.search-msms-settingsms-settings:screenrotationwindowsmediacenterapp
explorer.burnselectionms-settings:batterysaverms-settings:speechwindowsmediacenterssl
explorer.burnselectionexplorer.closesessionms-settings:batterysaver-settingsms-settings:storagesensewindowsmediacenterweb
explorer.closesessionms-settings:batterysaver-usagedetailsms-settings:windowsupdatewmp11.assocprotocol.mms
explorer.erasediscms-settings:bluetoothms-settings:workplacewsffile
explorer.zipselectionms-settings:connecteddevicesms-windows-storewsfile
filems-settings:cortanasearchms-wordwshfile
fonfilems-settings:datasenseocxfilexbls
hlpfilems-settings:dateandtimeofficezune
htafilems-settings:displayonenote
httpms-settings:lockscreenpiffile
httpsms-settings:mapsregfile
iehistoryms-settings:network-airplanemoderes
ierssms-settings:network-cellularrlogin
inffilems-settings:network-dialupscrfile
insfilems-settings:network-ethernetscriptletfile