Control the behavior for the cancel dialog produced by the beforeunload event (obsolete)
Verified with Microsoft Edge 152.0.4191.53 — updated on July 10, 2026
Supported on: Microsoft Edge version 118-130, Windows 7 or later
Path in the GPO console
Computer Configuration\Administrative Templates\Microsoft Edge User Configuration\Administrative Templates\Microsoft Edge Description
OBSOLETE: This policy is obsolete and doesn't work after Microsoft Edge 130. This policy provides a temporary opt-out for two related fixes to the behavior of the confirmation dialog that’s shown by the beforeunload event. If you've enabled this policy, the new (correct) behavior is used. If you've disabled this policy, the old (legacy) behavior is used. If you haven't configured this policy, the default behavior is used. Note: This policy is a temporary workaround and is going to be removed in a future release. New and correct behavior: In `beforeunload`, calling `event.preventDefault()` triggers the confirmation dialog. Setting `event.returnValue` to the empty string doesn’t trigger the confirmation dialog. Old and legacy behavior: In `beforeunload`, calling `event.preventDefault()` doesn’t trigger the confirmation dialog. Setting `event.returnValue` to the empty string triggers the confirmation dialog.
Registry
Software\Policies\Microsoft\Edge Software\Policies\Microsoft\Edge Value name: BeforeunloadEventCancelByPreventDefaultEnabled
Enabled: BeforeunloadEventCancelByPreventDefaultEnabled = 1
Disabled: BeforeunloadEventCancelByPreventDefaultEnabled = 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: Control the behavior for the cancel dialog produced by the beforeunload event (obsolete)
; State: Enabled
; Scope: Computer (HKLM)
; Supported on: Microsoft Edge version 118-130, Windows 7 or later
[HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Edge]
"BeforeunloadEventCancelByPreventDefaultEnabled"=dword:00000001More formats (PowerShell, Intune, SCCM)
PowerShell
# Exported from gporais.com
# Policy: Control the behavior for the cancel dialog produced by the beforeunload event (obsolete)
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: Microsoft Edge version 118-130, Windows 7 or later
$path = 'HKLM:\Software\Policies\Microsoft\Edge'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'BeforeunloadEventCancelByPreventDefaultEnabled' -Value 1 -Type DWordIntune XML
No direct Policy CSP / OMA-URI mapping for this policy. Use the Intune Remediation tab, or ingest the ADMX in Intune.Intune Remediation
# === Detection script ===
# Exported from gporais.com
# Policy: Control the behavior for the cancel dialog produced by the beforeunload event (obsolete)
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: Microsoft Edge version 118-130, Windows 7 or later
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
}
$checks = @(
(Test-RegistryValue -Path 'HKLM:\Software\Policies\Microsoft\Edge' -Name 'BeforeunloadEventCancelByPreventDefaultEnabled' -Expected 1 -Kind DWord)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Control the behavior for the cancel dialog produced by the beforeunload event (obsolete)
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: Microsoft Edge version 118-130, Windows 7 or later
$path = 'HKLM:\Software\Policies\Microsoft\Edge'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'BeforeunloadEventCancelByPreventDefaultEnabled' -Value 1 -Type DWordSCCM scripts
# Exported from gporais.com
# Policy: Control the behavior for the cancel dialog produced by the beforeunload event (obsolete)
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: Microsoft Edge version 118-130, Windows 7 or later
# 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: Control the behavior for the cancel dialog produced by the beforeunload event (obsolete)
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: Microsoft Edge version 118-130, Windows 7 or later
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
}
$checks = @(
(Test-RegistryValue -Path 'HKLM:\Software\Policies\Microsoft\Edge' -Name 'BeforeunloadEventCancelByPreventDefaultEnabled' -Expected 1 -Kind DWord)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Control the behavior for the cancel dialog produced by the beforeunload event (obsolete)
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: Microsoft Edge version 118-130, Windows 7 or later
$path = 'HKLM:\Software\Policies\Microsoft\Edge'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'BeforeunloadEventCancelByPreventDefaultEnabled' -Value 1 -Type DWordBuilding a multi-setting collection? Add this setting and generate combined .reg / PowerShell / GPO scripts.