Microsoft small business knowledge base

Article ID: 291369 - Last Review: September 23, 2011 - Revision: 7.0

This article was previously published under Q291369

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Internet Explorer versions 6, 7, and 8 include an "unsafe" file list that is coded in the Shdocvw.dll file. The purpose of the unsafe file list is to prevent you from accidentally opening a file type that could potentially cause problems on your computer.


The Internet Explorer unsafe file list has been updated to be consistent with the Microsoft Office unsafe file list. The following file types have been added to the unsafe file list:
Collapse this tableExpand this table
file extensionfile type
.adMicrosoft Access project extension
.adpAccess project
.crtSecurity certificate
.insInternet Naming service
.mdbAccess program
.mdeAccess MDE database
.mscMicrosoft Common Console document
.mspMicrosoft Windows Installer patch
.sct Windows script component
.shbShell scrap object
.vb VBScript file
.wscWindows script component
.wsf Windows script file
.cpl Control Panel extension
.shs Shell scrap object
.vsd Microsoft Visio file type
.vst Visio file type
.vss Visio file type
.vsw Visio file type
The complete unsafe file list in Internet Explorer includes the file types that are listed in the previous table, plus the following file types:
  • .asp
  • .bas
  • .bat
  • .chm
  • .cmd
  • .com
  • .exe
  • .hlp
  • .hta
  • .inf
  • .isp
  • .js
  • .jse
  • .lnk
  • .msi
  • .mst
  • .pcd
  • .pif
  • .reg
  • .scr
  • .url
  • .vbe
  • .vbs
  • .ws
  • .wsh
For more information about understanding executable content in Microsoft Products, visit the following Microsoft Web site: (

Modifying the Unsafe File List

For additional information on modifying the unsafe file list, click the article number below to view the article in the Microsoft Knowledge Base:
291387  ( ) OLEXP: Using Virus Protection Features in Outlook Express 6
For additional information about how to show file name extensions, click the following article number to view the article in the Microsoft Knowledge Base:
865219  ( ) How to show or hide file name extensions in Windows Explorer

  • Microsoft Internet Explorer 6.0, when used with:
    • Microsoft Windows Server 2003, Web Edition
    • Microsoft Windows Server 2003, Datacenter Edition (32-bit x86)
    • Microsoft Windows Server 2003, Enterprise Edition (32-bit x86)
    • Microsoft Windows Server 2003, Standard Edition (32-bit x86)
    • Microsoft Windows XP Home Edition
    • Microsoft Windows XP Professional
    • Microsoft Windows XP Media Center Edition 2005 Update Rollup 2
    • Microsoft Windows XP Tablet PC Edition
    • Microsoft Windows 2000 Advanced Server
    • Microsoft Windows 2000 Professional Edition
    • Microsoft Windows 2000 Server
    • Microsoft Windows NT Server 4.0 Standard Edition
    • Microsoft Windows NT Workstation 4.0 Developer Edition
  • Windows Internet Explorer 7
  • Windows Internet Explorer 8
kbinfo KB291369
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