Internet Explorer Processes
Verified with Windows 11 25H2 — updated on July 30, 2026
Supported on: At least Internet Explorer 6.0 in Windows XP with Service Pack 2 or Windows Server 2003 with Service Pack 1
Path in the GPO console
Computer Configuration\Administrative Templates\Windows Components\Internet Explorer\Security Features\Mime Sniffing Safety Feature User Configuration\Administrative Templates\Windows Components\Internet Explorer\Security Features\Mime Sniffing Safety Feature Description
This policy setting determines whether Internet Explorer MIME sniffing will prevent promotion of a file of one type to a more dangerous file type. If you enable this policy setting, MIME sniffing will never promote a file of one type to a more dangerous file type. If you disable this policy setting, Internet Explorer processes will allow a MIME sniff promoting a file of one type to a more dangerous file type. If you do not configure this policy setting, MIME sniffing will never promote a file of one type to a more dangerous file type.
Registry
HKLM
Software\Policies\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_MIME_SNIFFING HKCU
Software\Policies\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_MIME_SNIFFING This policy sets several registry values:
(Reserved) Enabled:
(Reserved) = 1 Disabled:
(Reserved) = 0 explorer.exe Enabled:
explorer.exe = 1 Disabled:
explorer.exe = 0 iexplore.exe Enabled:
iexplore.exe = 1 Disabled:
iexplore.exe = 0 MDM / Intune (CSP)
Device
./Device/Vendor/MSFT/Policy/Config/InternetExplorer/MimeSniffingSafetyFeatureInternetExplorerProcesses User
./User/Vendor/MSFT/Policy/Config/InternetExplorer/MimeSniffingSafetyFeatureInternetExplorerProcesses Microsoft Learn documentation Mapping data: Microsoft Learn (CC BY 4.0)
Export Builder
BETAConfigure the state, scope and options, then generate .reg, PowerShell, Intune and SCCM outputs — or add the setting to a multi-setting collection.
These exports write the registry — this is not a managed GPO. ⓘ
Applying both scopes creates an ambiguous configuration (computer takes precedence over user). Only do this intentionally.
.reg file
Windows Registry Editor Version 5.00
; Exported from gporais.com
; Policy: Internet Explorer Processes
; State: Enabled
; Scope: Computer (HKLM)
; Supported on: At least Internet Explorer 6.0 in Windows XP with Service Pack 2 or Windows Server 2003 with Service Pack 1
[HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_MIME_SNIFFING]
"(Reserved)"="1"
"explorer.exe"="1"
"iexplore.exe"="1"More formats (PowerShell, Intune, SCCM)
PowerShell
# Exported from gporais.com
# Policy: Internet Explorer Processes
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: At least Internet Explorer 6.0 in Windows XP with Service Pack 2 or Windows Server 2003 with Service Pack 1
$path = 'HKLM:\Software\Policies\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_MIME_SNIFFING'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name '(Reserved)' -Value '1' -Type String
Set-ItemProperty -Path $path -Name 'explorer.exe' -Value '1' -Type String
Set-ItemProperty -Path $path -Name 'iexplore.exe' -Value '1' -Type StringIntune XML
OMA-URI: ./Device/Vendor/MSFT/Policy/Config/InternetExplorer/MimeSniffingSafetyFeatureInternetExplorerProcesses
Data type: String
Value:
<enabled/>Intune Remediation
# === Detection script ===
# Exported from gporais.com
# Policy: Internet Explorer Processes
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: At least Internet Explorer 6.0 in Windows XP with Service Pack 2 or Windows Server 2003 with Service Pack 1
function Test-RegistryValue {
param(
[Parameter(Mandatory = $true)][string]$Path,
[Parameter(Mandatory = $true)][string]$Name,
[object]$Expected,
[ValidateSet('String', 'DWord', 'MultiString')][string]$Kind = 'String',
[switch]$Absent
)
try {
$item = Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction Stop
} catch {
return $Absent.IsPresent
}
if ($Absent.IsPresent) { return $false }
$actual = $item.$Name
if ($Kind -eq 'DWord') { return ([int64]$actual) -eq ([int64]$Expected) }
if ($Kind -eq 'MultiString') {
$actualValues = @($actual)
$expectedValues = @($Expected)
if ($actualValues.Count -ne $expectedValues.Count) { return $false }
for ($i = 0; $i -lt $expectedValues.Count; $i++) {
if ([string]$actualValues[$i] -ne [string]$expectedValues[$i]) { return $false }
}
return $true
}
return [string]$actual -eq [string]$Expected
}
$checks = @(
(Test-RegistryValue -Path 'HKLM:\Software\Policies\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_MIME_SNIFFING' -Name '(Reserved)' -Expected '1' -Kind String)
(Test-RegistryValue -Path 'HKLM:\Software\Policies\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_MIME_SNIFFING' -Name 'explorer.exe' -Expected '1' -Kind String)
(Test-RegistryValue -Path 'HKLM:\Software\Policies\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_MIME_SNIFFING' -Name 'iexplore.exe' -Expected '1' -Kind String)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Internet Explorer Processes
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: At least Internet Explorer 6.0 in Windows XP with Service Pack 2 or Windows Server 2003 with Service Pack 1
$path = 'HKLM:\Software\Policies\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_MIME_SNIFFING'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name '(Reserved)' -Value '1' -Type String
Set-ItemProperty -Path $path -Name 'explorer.exe' -Value '1' -Type String
Set-ItemProperty -Path $path -Name 'iexplore.exe' -Value '1' -Type StringSCCM scripts
# Exported from gporais.com
# Policy: Internet Explorer Processes
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: At least Internet Explorer 6.0 in Windows XP with Service Pack 2 or Windows Server 2003 with Service Pack 1
# SCCM Configuration Item guidance:
# Create a Configuration Item of type "Setting: Script".
# Discovery script: use the Detection script below.
# Remediation script: use the Remediation script below.
# Compliance rule: the Discovery script output equals 'Compliant'.
# === Detection script ===
# Exported from gporais.com
# Policy: Internet Explorer Processes
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: At least Internet Explorer 6.0 in Windows XP with Service Pack 2 or Windows Server 2003 with Service Pack 1
function Test-RegistryValue {
param(
[Parameter(Mandatory = $true)][string]$Path,
[Parameter(Mandatory = $true)][string]$Name,
[object]$Expected,
[ValidateSet('String', 'DWord', 'MultiString')][string]$Kind = 'String',
[switch]$Absent
)
try {
$item = Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction Stop
} catch {
return $Absent.IsPresent
}
if ($Absent.IsPresent) { return $false }
$actual = $item.$Name
if ($Kind -eq 'DWord') { return ([int64]$actual) -eq ([int64]$Expected) }
if ($Kind -eq 'MultiString') {
$actualValues = @($actual)
$expectedValues = @($Expected)
if ($actualValues.Count -ne $expectedValues.Count) { return $false }
for ($i = 0; $i -lt $expectedValues.Count; $i++) {
if ([string]$actualValues[$i] -ne [string]$expectedValues[$i]) { return $false }
}
return $true
}
return [string]$actual -eq [string]$Expected
}
$checks = @(
(Test-RegistryValue -Path 'HKLM:\Software\Policies\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_MIME_SNIFFING' -Name '(Reserved)' -Expected '1' -Kind String)
(Test-RegistryValue -Path 'HKLM:\Software\Policies\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_MIME_SNIFFING' -Name 'explorer.exe' -Expected '1' -Kind String)
(Test-RegistryValue -Path 'HKLM:\Software\Policies\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_MIME_SNIFFING' -Name 'iexplore.exe' -Expected '1' -Kind String)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Internet Explorer Processes
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: At least Internet Explorer 6.0 in Windows XP with Service Pack 2 or Windows Server 2003 with Service Pack 1
$path = 'HKLM:\Software\Policies\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_MIME_SNIFFING'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name '(Reserved)' -Value '1' -Type String
Set-ItemProperty -Path $path -Name 'explorer.exe' -Value '1' -Type String
Set-ItemProperty -Path $path -Name 'iexplore.exe' -Value '1' -Type StringBuilding a multi-setting collection? Add this setting and generate combined .reg / PowerShell / GPO scripts.