Thanks y'all for trying to help but I think my only solution is to buy a new PC with Windows 10 because anything with XP is not supported anymore therefor none of the links to solutions for XP exist. It is a mystery. I am able to download some new software, but others get stuck halfway. I think I'm on a roll but then STUCK !! Microsoft Fix-it no longer exists for XP.

Check if your system can be upgraded.

Sorry to see you think this way. If MS offered an update that messed up my system, I would not think of buying a new PC with any OS of them, and certainly not Windows 10. And that’s regardless of their (contributors?) non-efforts to help someone in their forum. Part of an update policy? :)

True, many software and XP itself is no longer supported and of course you could buy a new one, but it would not prevent me from using that system as a second one and making sure it still works, which would be a small challenge in this case. And of course I’d report back on their forum what fixed it and say thank you for the help. Speaking of, did you think of responding there and focus on the MSE issue only? They should know their so-called "MVP / Insider" response is a shame to see for users, though I’ve seen many more of them there.

- Is there really nothing in the links provided that works? - Did you consider uninstalling the recent MS patch(es) that caused this? (I think it is KB4012583) - Did you consider creating another user account? - Did you consider reinstalling XP?

If you really want to upgrade and your hardware allows it, I’d recommend doing a fresh Windows 7 install, not as an upgrade (to an OS that has issues.)

Note that you should be cautious with reinstalling XP, because all updates that you have installed over time might not be available any more. If you would reinstall XP then I would recommend to do a full backup and check whether you can locate important updates on internet (that would be a good idea anyway).

Tonnes, thanks for a simple suggestion. I didn't know you could uninstall Microsoft Updates. I trusted Microsoft to know what Updates my XP SP3 system warranted. I do not have KB4012583 on my PC looking at Microsoft Update History or Control Panel Add/Remove Programs & Windows Components. Should I install it from the Microsoft Update website??? I have uninstalled all the updates (for programs I don't even have on my PC, like Office 2007) from the 7/13/17 Update. Was not instructed to reboot, tried Firefox still won't open when launched, but 81,196k in memory - no CPU usage in task manager. IE does launch and open now but it didn't before ~ so that's a WIN. However I do not use it because of security issues with it and XP. I do not have XP install discs as the PC came with it installed. I have created another User Account (also as Administrator privilege). I have rebooted (even though it didn't direct me to do so). The NEW added User Account I set up still will not allow Firefox to open when launched, but it does show in task manager memory usage.

You said that Firefox is not opening, but is listed in the Task Manager? It might be that the window is opening outside where you can see it.

Open Firefox. Now right-click the icon and select Open In New Window. If this works, close the First window. Then close the program.

Then reopen.

FredMcD yep that is what I said at the very beginning of this PROBLEM. There is no option "Open in New Window" when right clicking on the Firefox Icon, just OPEN. If I right click and select RUN AS it still does not open a window anywhere but is listed another time in Task Manager. I know you can move windows off the screen accidently but that is not the issue here.

IE will launch and open, Chrome will launch and open. Both take forever. I don't use either of these because of no MS support or Updates in XP. Firefox will launch but NOT OPEN. I also had an issue with svchost using 100% CPU so I fixed that by changing Automatic Update to disable & stop. At least now I have some CPU processing and Idle Process is 97%. Firewall is off in Control Panel because AVG is controlling my Firewall (I hope). Additionally when trying to download latest 64bit version of Firefox 54.0.1, it STOPS at .2/45.7MB. My current version of it is 32bit 52.2.1esr. NO HELP ON THE MICROSOFT SUPPORT SITE YET - been 4 days

Have you thought of using Firefox ESR? It should work with XP.

Firefox; Extended Support Release {web link} ESR Notes System Requirements

FredMcD, I had Firefox 52.2.1esr installed and I went back to 52.0.2esr and it didn't fix the problem that I thought the 52.2.1esr was causing. So neither of these versions when launched give me a Firefox window. It never opens and memory usage varies but never any CPU usage (always 0).

https://ftp.mozilla.org/pub/firefox/releases/45.9.0esr/

Did you uninstall the anti-virus product yet?

Again, I would make sure the system is as clean as possible with regard to networking, so just uninstall that, preferably when logged on as Administrator. If you can only run Firefox in Safe mode as Administrator like you wrote earlier, that’s some indication. Don’t be scared (again, only if you are on a LAN behind a router), just do it - it’s simply required for troubleshooting. After all, one updated system file could break functionality of a security product, or require you to reinstall it - provided that the security software is still available and updated for XP even after new XP <strike>jokes</strike> patches from MS.

After uninstalling AVG as well as any other security/malware/spyware software (since they may contain features interfering networking), reboot and (only) enable Windows Firewall at most. For easy Firefox Safe Mode access, you can copy the Firefox shortcut on your desktop for the newly created user account and modify it to -safe-mode at the end and outside the quotes (e.g. "C:\Program Files\Mozilla Firefox\firefox.exe" -safe-mode). All this is to see if you can get as far as when logged in as Administrator previously, but without additional software.

Also check the Internet Options - Connection - LAN settings section in IE or Windows Control panel to use No proxy if any of these options are set and ticked (just unselect everything.) Firefox uses system proxy settings by default so if they are not set up correctly, you can get the timeouts you see in Firefox Safe Mode. Not being able to use its regular mode may be because of the security software.

Did you try the steps I posted earlier? What are the results for fixing SFC for instance? Please try to provide feedback to steps provided, or helpers may stop find other methods as they don’t know what you did and dit not try. If some step or action seems scary, don’t just skip it like some users do. ;)

You probably can’t uninstall the KB update from the Update website, it’s something local. Also, that KB update number may be a summary for several other updates that should be visible in the Update log out of which only one is responsible - I didn’t check - and of course you could uninstall any update after or from around a particular date when the issue started. It would be nice to pinpoint the exact patch (and report back in the MS forum), but the issue could or will probably return after reinstalling it so finding out what is required to make things work now may be better and serves you more. Trying Firefox 64-bit is probably useless if your XP is 32-bit, and should not be the way to fix this issue even if it was 64-bit. FF should just run, as well as other browsers. This is clearly not a Firefox issue.

You did try all suggestions from the Firefox won't start - find solutions article didn’t you? Also have a look at the mozillaZine KB article refered to at the bottom. That mentions Windows specific issues such as the ones with ZoneAlarm (note what that is able to cause) as well as a fix to a Microsoft issue. You could also have a look at the Windows system/application/security logs using the Event viewer, though I think the startup issue will not be listed. If you check the logs, also look for other applications errors, not limited to Firefox.

I already refered to steps for resetting the TCP/IP stack and saw no feedback (again, please provide it.) Additionally you could try resetting the firewall and winsock as explained here.

As for the MS forum, I would reply and say you are not happy about them not offering a solution or explanation for your Windows (not Firefox) issue. You will likely get a default response for fixing the MSE related errors only (at most), but that may just be what you need. Chances are nobody will reply by itself after the current single "MVP" reply.

FredMcD said

https://ftp.mozilla.org/pub/firefox/releases/45.9.0esr/

OMG....FredMcD, what a simple ANSWER/FIX this was to down-date Firefox to this lower 32bit version that truly works with XP SP3. However as soon as I got my open window I was prompted to update to Firefox 52.2.1esr, but I will not be doing that. The notes say this version is intended for groups who deploy and maintain desktop environments in large organizations. I am 1 desktop gateway with wifi laptop and cellphones.

There is a big gap in version numbers from 45.X.X to 52.2.1 but I couldn't find any, so will stick with 45.9.0esr for now.

THANK YOU♥♥THANK YOU♥♥THANK YOU

Evidently all the other stuff we tried was superfluous. I wonder if any of it actually hurt (made less secure) my PC or my AVG security, Malwarebytes, or Spyware at all. Hope NOT !!

Type about:preferences#advanced<enter> in the address bar.

Under Advanced, Select Update. Check the settings.

Also turn off Use a background service to install updates

This sounds more like a coincidence by a workaround than a solid solution that will not fix your other issues and may cause you to run into others. Remember 52.0.2 worked fine for you previously, and so should 52.2.1esr (it does here on XP SP3.) To be sure, you should let it update to 52.2.1esr or install 52.0.2esr instead - you could always uninstall and revert to this 45.9.0esr version or the previous 52.0.2esr anyway.

ESR is not intended for business users only, it’s for any user not allowed to update - due to company restrictions defining what version to use rather than allowing each employee to use its preferred version - or users not capable of updating due to hardware or OS - this includes you. I’m also convinced that the other stuff was not superfluous at all and your PC is hurt indeed.

_{I don’t write this because of my or other people’s time spent on this issue, lack of feedback or annoyance. I do however appreciate solid solutions that work for anyone suffering the same issue that finds this question, as well as finding real causes and culprits in general.}

FredMcD said

Type about:preferences#advanced<enter> in the address bar. Under Advanced, Select Update. Check the settings. Also turn off Use a background service to install updates

THERE IS NO "Use a background service to install updates" in Advanced, Update, (Firefox updates: only *Automatically install *Check for updates, let me choose, *Never check for updates. And I unchecked "search engines" under Automatically update:.

So where is this "Use a background service to install updates" ???

Tonnes, I understand what you said and I will try one of the upgrades to the newer versions. I understand I can always go back (as I've already done). I am leaving for the weekend so will try this on Monday or Tuesday next week. Thanks for all your help and suggestions. This has been a long road for all of us. Things should not be this hard, period. I seriously was ready to go out and get a new PC with Win10, but I like XP so much. I even had CenturyLink come out to troubleshoot my ISP service, which uncovered nothing. Thanks again. I will update the final results after I try it early next week.