Six weeks ago when I updated MSIE from v10.0 to v11.0 my default browser setting was changed from Firefox to MSIE. When I went to switch default browser setting back to Firefox, it wouldn't work, neither via Firefox Options screen nor by Default Program control panel applet. I'm able to set Firefox to be the default program for opening all common hypertext file types but I can't make it the default program for handling internet protocols (FTP, HTML and HTMLS). Windows Control Panel applet "Default Programs" allows three methods for making these changes:
1.) Set your program defaults
Clicking this option opens a list of programs, including all browsers installed on system, and allows user to either choose one browser to open all file types and protocols or to assign file types and protocols piecemeal to desired browser(s). I used both options to assign Fifefox the job of handling protocols but the system didn't register my choices, keeping MSIE as the protocol handler. I tried UNselecting MSIE as the protocol handler but the checked boxes were grayed out and could not be unchecked.
2.) Associate a file type or protocol with a program
Clicking this option lists all registered file types and protocols and allows users to assign a specific program to handle individual file types and protocols. I assigned all three protocols to Firefox but again the system did not register the changes.
3.) Set program access and computer defaults
Clicking this option opens a screen where the user can not only assign a specific browser to handle all internet file types and protocols but also allows user to revoke access to MSIE altogether. I chose Firefox as the default browser and denied access to MSIE. Windows notified me that it had made the requested changes but again did not save the changes. MSIE remained not only accessible but remained the default browser.
Curiously, the MSIE Options tab states that MSIE is not the default browser. I set Firefox to be the default browser every time the browser runs but Windows doesn't recognize my request, not even for that one browsing session. Clicking URLs or shortcuts always launches MSIE.
I've attempted to use Regedit to make the necessary registry changes directly. Unfortunately, Regedit won't let me edit those particular values, even when I'm running Regedit with Administrator privileges. I've used a Tweaking.com app to reset all registry privileges but it didn't help.
I am running Windows 7 Premium Home Edition (sp1) 64-bit on a Hewlett-Packard desktop PC with plenty of free disk space (Total 932 GB, Used 63 GB), 2.90 GHz ADM Phenom II X4 840T Processor, 6 GB RAM. My internet firewall is handled by Norton360 and Firefox is approved to access the internet.
I've scanned my system with Norton 360, ClamWin, Emsisoft, Sophos, HitMan Pro, Malwarebytes Antimalware, SuperAntispyware, and a few rootkit scanners, and found nothing.
I've uninstalled/reinstalled Firefox v25.01 stable version.
I've rolled back MSIE from v11.0 to v10.0 and when that didn't work I rolled v10.0 back to v9.0.
I've attempted to indirectly change my system's default browser setting using programs like Auslogics Browser Care.
I've tried to wrest the default browser setting away from MSIE by installing additional browsers (Google Chrome and Opera), and setting each of them (during and after install) to be the default browser for opening internet URLs.
None of these things worked. So, at one point I had 4 browsers on my system (MSIE, Firefox, Chrome, Opera), each of which stated (via their configuration screens) that they were not the system's default browser. Even MSIE, which has in fact been the system's default browser for the last 6 weeks, has never identified itself as the default browser. Very strange.
I really don't want to roll my system back six weeks (back to a time before the start of the problem) using a backup disk image. Anyone have any ideas, maybe a shot in the dark, a guess... anything?
Please note that this is an edited post (technically a repost because I don't have the "Edit" button). A few weeks ago I read somewhere on this site that it's OK to repost as long as 1.) the poster has added additional useful information (I've done that) and 2.) the "timer" has not run out. I'm at a complete loss as to what this second requirement means so in the event that I've transgressed forum rules, I apologize. Even after rereading the FAQ again I was also unsure as to whether I should post this as a new thread or repost it in the old thread. So, again, I'm sorry if I screwed up.