Allow unconfigured sites to be reloaded in Internet Explorer mode
This value is a Boolean Microsoft Edge policy represented as `REG_DWORD`.
since 0.9.8.11
Purpose
Show registry keys (1)
HKLM\Software\Policies\Microsoft\Edge\InternetExplorerIntegrationReloadInIEModeAllowed
This value is a Boolean Microsoft Edge policy represented as REG_DWORD. A value of 0 disables manual reloading of unconfigured sites in Internet Explorer mode.
Sites explicitly approved for IE mode can still open according to the existing IE mode configuration. This value does not disable IE mode itself or the centrally managed site list.
Notes
Security
IE mode uses the Internet Explorer 11 Trident/MSHTML engine for legacy web applications. Microsoft identifies this legacy engine as less secure than the modern Edge browser engine and advises limiting its use to trusted sites.
Setting the value to 0 prevents users from manually loading arbitrary, centrally unapproved sites with the legacy engine. It therefore confines IE mode use to sites authorized through other policies. It does not mitigate vulnerabilities in approved sites or prevent those sites from running in IE mode.
Possible side effects
Users cannot manually fall back to IE mode for a legacy site or web application that is absent from the applicable site list and incompatible with the modern Edge engine. Such applications may remain unusable until they are included in the centrally managed configuration.
Notes
The policy is supported on Windows beginning with Microsoft Edge 92. It does not support dynamic policy refresh, so a browser restart is required before a change takes effect.
Microsoft documentation
Microsoft Learn: Allow unconfigured sites to be reloaded in Internet Explorer mode
Microsoft Learn: Modern security protection for vulnerable legacy apps