Hello,

Firefox wouldn't automatically change to a different search configuration during an upgrade unless something was wrong. If search / home page etc changes without your permission then it is most likely a malware / virus issue.

Please see the following support articles for help:

• Troubleshoot Firefox issues caused by malware
• What to do when searches take you to the wrong search website
• Remove a toolbar that has taken over your Firefox search or home page

I hope that helps.

Thanks for the reply. However, I am still confused. As a non-techie, I struggle with lengthy or complex descriptions of various issues and solutions, and the Troubleshoot links you gave left me feeling more baffled than clear on what to do. I did go to Mozilla and reinstall the 25.0.1 version, which now seems to show a more typical Firefox start page and has Google as the default search engine showing in the upper right.

But some of the browser's behavior remains weird. The install driver remained on the desktop, wouldn't eject, and when I finally trashed it after install, the Firefox icon wouldn't stay in the dock after quitting it as usual. When I close out of the browser but it remains activated in the dock (which is normal), I click on the Firefox icon in the dock again and the home page doesn't load, even though the Firefox menu bar is at the top and I can click on bookmarks or whatever to open it. Many times the browser has seemed to stick in certain ways and won't let me click on the icon in the dock to Quit, so I have to Force Quit from the main Apple menu bar. I'm concerned that there's some malware or other bad actor in play. But I don't know how to determine that or fix it.

When I downloaded the latest Firefox version a few days ago, I remember it came up in the course of something I was doing, maybe in Yahoo account. I've had problems with the yahoo account in its new form, by the way. I ran disk repair, restarted the computer, but continue to have issues that are bogging down my normal activity on the web and even third-party software like Photoshop. It's been frustrating.

I have been running 10.6.8 for awhile and started to have some issues with the browser sticking and the machine freezing up at times lately, soon after installation of a new memory module. But this seems to occur about once a day, with the spinning wheel running as if trying to load something and not finishing the action, then it will behave more normally the rest of that day. All of this strikes me as suspicious and maybe due to some malware or virus, but I've always been told by Apple folks that the OS is already set up to resist that kind of thing and I shouldn't do anything more. The links you gave address some of this, but it's a lot of information, much of it beyond me or just kind of overwhelming.

I'd welcome any suggestions for how to determine if my machine is affected by something and how to resolve it without too much complication. Thanks.

Oh, one more thing. I did follow one of the instructions in the link you gave and removed a couple of toolbars, one for Yahoo connections and one related to a recent download of a youtube downloader for video which I wasn't using and didn't realize it was there. (I do use a Download Helper plugin, which does show in the toolbar to the far right and has been helpful since I downloaded it about a month ago, but I'm not positive it didn't bring some bug with it, either.) Anyway, the toolbar in the browser now looks as I'm used to.

Glad it seems to be fixed. I note from the system information that you provided that you did have a Yahoo toolbar installed.

I will mark eddyc's answer as the solution.Should you have any further problem you can unmark that and ask again.