From Bugzilla Helper: User-Agent: Mozilla/5.0 (Windows; U; Win98; en-US; rv:1.0rc1) Gecko/20020417 BuildID: 2002041711 Mozilla is trying to take over MSIE monopoly!!! (Horrors...) If I go to Preferences|Advanced|System and simply press OK, IE 5.0 starts to complain that it is not the default browser any more. I have nothing checked from the extensions/protocols list. Reproducible: Always Steps to Reproduce: 1. Go to the System preferences, uncheck everything, run IE and make it the default browser for everything. (I'm not sure how much of this is really needed). 2. Open the System preferences, and press OK. 3. Run IE. It should complain. Actual Results: IE complained that it's not the default browser any more. Expected Results: Mozilla shouldn't have changed the registry at all.

Output of Regmon, www.sysinternals.com

*** Bug 150066 has been marked as a duplicate of this bug. ***

Choosing OK means "apply preference settings and exit the preferences dialog," and you have items checked in the System preferences panel. The problem is that the System panel does not properly reflect the actual system settings. Change summary to "Preferences > Advanced > System should reflect actual system settings"

*** Bug 193128 has been marked as a duplicate of this bug. ***

Mozilla/5.0 (Windows; U; Win98; en-US; rv:1.7.12) Gecko/20050915 Note that "open" an HTML file means to display it in a browser. Thus, my [Advanced > System] preferences indicate to use Mozilla to open an HTML file. "Edit" an HTML file means something quite different. I have set my Windows [View > Folder Options > File Types] to edit HTML files in Wordpad since I manually code all my HTML. Because of this bug, selecting OK on [Advanced > System] causes the HTML file association to change to use Composer as my editor. It appears that "open" includes "edit", which is quite wrong. Question: Is this also a Firefox problem?

(Filter "spam" on 'prefs-nobody-20080612'.)

That UI is gone now, so closing this bug