Windows Registry key for "check whether IE is the default browser"?

Question

In IE under Tools-> Internet Options -> Programs there's a checkbox labelled "Tell me if Internet Explorer is not the default web browser." What's the registry key that corresponds to this checkbox? The reason I ask is that I want to suppress this check programmatically.

Clarification: I don't want to find out the default browser, I want to stop IE checking if it is the default browser when it starts up.

Solution 1

It's been answered in various ways over the web and here; here's one question which covers it; Windows RegKey - Default Browser Application Path. Then it's just checking if the path is the iexplore.exe path.

Update: I just checked what the key is that is modified when you deselect and reselect the "check default browser" option.

When you deselect it, the value HKCU\Software\Microsoft\Internet Explorer\Main\Check_Associations is created, a REG_SZ containing the string "no".

When you reselect it, HKCU\Software\Microsoft\Internet Explorer\Main\Check_Associations is altered to "yes".

So: if HKCU\Software\Microsoft\Internet Explorer\Main\Check_Associations does not exist or is "yes", it will check. To avoid that check (potentially user-unfriendly behaviour - use with care - create as "no" or set to "no" the value HKCU\Software\Microsoft\Internet Explorer\Main\Check_Associations.

Solution 2

For those trying to defeat corporate group policy, this does the trick in one command

reg add "HKCU\Software\Microsoft\Internet Explorer\Main" /f /v "Check_Associations" /d "no" /t REG_SZ

Solution 3

There are two keys:

• HKEY_LOCAL_MACHINE\SOFTWARE\Classes\.htm
• HKEY_LOCAL_MACHINE\SOFTWARE\Classes\.html

Change the Default Key value to: htmlfile or ChromeHTML

Not sure about Firefox, but if you set it here, you will not be asked.