Use Pop-up Blocker

Purpose

Show registry keys (2)

• HKLM\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\4\1809
• HKCU\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\4\1809

The 1809 registry value controls Pop-up Blocker for websites in the Restricted Sites security zone (zone 4). It is a REG_DWORD value: 0 turns on Pop-up Blocker, while 3 turns it off.

When Pop-up Blocker is on, the Internet Explorer web platform prevents most unwanted pop-up windows from appearing. Pop-up windows opened as a direct result of the user clicking a link remain allowed.

The HKLM value applies at the computer level, while the HKCU value applies to the individual user.

Notes

Security

Turning on Pop-up Blocker reduces the ability of a site to open unsolicited browser windows containing deceptive, intrusive, or potentially harmful content. It does not provide general protection against scripts, redirects, or malicious web content.

When the value is set to 3, this particular protection is removed for the Restricted Sites zone, and pop-up windows that were not initiated by the user are not suppressed by this setting.

Possible side effects

Web applications that open new windows without an immediate user click might not work as intended when Pop-up Blocker is on. Automatically opened dialogs, notifications, or auxiliary windows can be affected.

Notes

This setting applies only to content assigned to the Restricted Sites zone and processed by the Internet Explorer web platform. It does not configure pop-up handling for ordinary Microsoft Edge pages rendered by the Chromium engine or for other browsers.

Internet Explorer mode in Microsoft Edge continues to evaluate Internet Explorer security-zone settings. The value can therefore also affect pages running in IE mode.

Microsoft documentation

Microsoft Learn: InternetExplorer Policy CSP – RestrictedSitesZoneUsePopupBlocker

Microsoft Learn: What is Internet Explorer mode?

See also

• Entry in the reference