Sometimes a problem with Firefox may be a result of malware installed on your computer, that you may not be aware of.

You can try these free programs to scan for malware, which work with your existing antivirus software:

• Microsoft Safety Scanner
• MalwareBytes' Anti-Malware
• Anti-Rootkit Utility - TDSSKiller (for more info, see this alternate TDSSKiller download page)
• AdwCleaner (for more info, see this alternate AdwCleaner download page)
• Hitman Pro
• ESET Online Scanner

Microsoft Security Essentials is a good permanent antivirus for Windows 7/Vista if you don't already have one. Windows 8/10 have antivirus protection built-in.

Further information can be found in the Troubleshoot Firefox issues caused by malware article.

Did this fix your problems? Please report back to us!

SnapMyScreen is well known "garbage" that will cause problems for users. References to that statement.

https://www.adaware.com/blog/how-to-remove-snapmyscreen

https://www.pcrisk.com/removal-guides/8442-snapmyscreen-toolbar

https://www.securitystronghold.com/gates/remove-snapmyscreen-toolbar.html

https://www.fixyourbrowser.com/removal-instructions/remove-snapmyscreen-toolbar-uninstall-instruction/

It’s very sad, but many software downloaders/ installers will trick you into installing not only their program, but other programs as well.

You have heard of the fine print in shady contracts, right? Well, some installers you need to look at the itsy bitsy teeny weeny fine print.

You are thinking you are giving the installer permission to install the program you want by using the recommended option. But if you use the Manual Option Instead, you discover all kinds of stuff that you do not even know what it is or what it does.

From now on, everyone needs to Use The Manual Option to put a stop to this.

Note that these programs can also change browser/computer settings.

the-edmeister said

SnapMyScreen is well known "garbage" that will cause problems for users. References to that statement. https://www.adaware.com/blog/how-to-remove-snapmyscreen https://www.pcrisk.com/removal-guides/8442-snapmyscreen-toolbar https://www.securitystronghold.com/gates/remove-snapmyscreen-toolbar.html https://www.fixyourbrowser.com/removal-instructions/remove-snapmyscreen-toolbar-uninstall-instruction/

Thanks, but these only work if you can SEE SnapMyScreen in the add-ons or extensions folders. I wrote in my initial question that my computer can't find SnapMyScreen and neither can Firefox. It's hidden itself. So I need better anti-malware, but now I'm afraid to use anything for fear that it's just more malware. Sigh.

FredMcD said

It’s very sad, but many software downloaders/ installers will trick you into installing not only their program, but other programs as well. You have heard of the fine print in shady contracts, right? Well, some installers you need to look at the itsy bitsy teeny weeny fine print. You are thinking you are giving the installer permission to install the program you want by using the recommended option. But if you use the Manual Option Instead, you discover all kinds of stuff that you do not even know what it is or what it does. From now on, everyone needs to Use The Manual Option to put a stop to this. Note that these programs can also change browser/computer settings.

Hi - I agree, but how do you use the manual option when the malware has hidden itself? Neither my computer nor Firefox can find SnapMyScreen. And please remember that I don't know much about computers if you reply! Many thanks.

Hey there, the anti-malware scanners I posted in my initial reply are trusted and are used by the community :)

Could you try starting Firefox in its Safe Mode? In Safe Mode, Firefox temporarily deactivates extensions, hardware acceleration, and some other advanced features to help you assess whether these are causing the problem.

If Firefox is not running: Hold down the Shift key when starting Firefox.

If Firefox is running: You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" button > Restart with Add-ons Disabled
• Help menu > Restart with Add-ons Disabled

and OK the restart.

Both scenarios: A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Any improvement?

Note: If you get an unwanted startup page, don't close Firefox, try this this next:

• Ctrl+n to launch a new window -- same issue or normal home page?

• In the Windows 10 search box, paste this and press Enter to execute it:
  firefox.exe "about:newtab"

CluelessinCali said

Today, SnapMyScreen installed itself on Mozilla, and now nothing loads on Mozilla. SnapMyScreen doesn't show up in the Extensions section of Mozilla. It also doesn't show up anywhere on my computer, even though I enabled my Search functions to show hidden files and folders. [which I learned to do today from a YouTube video!] I have almost no understanding of technical computer stuff, so if you reply, please try to use layman's terms. Many thanks!

Thank you! I did decide to go ahead and use them. I got rid of the SnapMyScreen but still can't run Firefox. I'm going to try to open it in Safe mode. If that doesn't work, I guess I can uninstall & reinstall it. Totally appreciate your input.

jscher2000 said

Could you try starting Firefox in its Safe Mode? In Safe Mode, Firefox temporarily deactivates extensions, hardware acceleration, and some other advanced features to help you assess whether these are causing the problem. If Firefox is not running: Hold down the Shift key when starting Firefox. If Firefox is running: You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" button > Restart with Add-ons Disabled
• Help menu > Restart with Add-ons Disabled

and OK the restart. Both scenarios: A small dialog should appear. Click "Start in Safe Mode" (not Refresh). Any improvement? Note: If you get an unwanted startup page, don't close Firefox, try this this next:

• Ctrl+n to launch a new window -- same issue or normal home page?

• In the Windows 10 search box, paste this and press Enter to execute it:
  firefox.exe "about:newtab"

Thanks so much for your response. I opened Firefox in safe mode and still can't get online. I think uninstalling is my only option at this point.

CluelessinCali said

FredMcD said

It’s very sad, but many software downloaders/ installers will trick you into installing not only their program, but other programs as well. You have heard of the fine print in shady contracts, right? Well, some installers you need to look at the itsy bitsy teeny weeny fine print. You are thinking you are giving the installer permission to install the program you want by using the recommended option. But if you use the Manual Option Instead, you discover all kinds of stuff that you do not even know what it is or what it does. From now on, everyone needs to Use The Manual Option to put a stop to this. Note that these programs can also change browser/computer settings.

Hi - I agree, but how do you use the manual option when the malware has hidden itself? Neither my computer nor Firefox can find SnapMyScreen. And please remember that I don't know much about computers if you reply! Many thanks.

Hi again - I got SnapMyScreen off w/antimalware software. Many thanks!

CluelessinCali said

FredMcD said

It’s very sad, but many software downloaders/ installers will trick you into installing not only their program, but other programs as well. You have heard of the fine print in shady contracts, right? Well, some installers you need to look at the itsy bitsy teeny weeny fine print. You are thinking you are giving the installer permission to install the program you want by using the recommended option. But if you use the Manual Option Instead, you discover all kinds of stuff that you do not even know what it is or what it does. From now on, everyone needs to Use The Manual Option to put a stop to this. Note that these programs can also change browser/computer settings.

Hi - I agree, but how do you use the manual option when the malware has hidden itself? Neither my computer nor Firefox can find SnapMyScreen. And please remember that I don't know much about computers if you reply! Many thanks.

Hi again - I got SnapMyScreen off w/antimalware software. Many thanks!CluelessinCali said

FredMcD said

It’s very sad, but many software downloaders/ installers will trick you into installing not only their program, but other programs as well. You have heard of the fine print in shady contracts, right? Well, some installers you need to look at the itsy bitsy teeny weeny fine print. You are thinking you are giving the installer permission to install the program you want by using the recommended option. But if you use the Manual Option Instead, you discover all kinds of stuff that you do not even know what it is or what it does. From now on, everyone needs to Use The Manual Option to put a stop to this. Note that these programs can also change browser/computer settings.

Hi - I agree, but how do you use the manual option when the malware has hidden itself? Neither my computer nor Firefox can find SnapMyScreen. And please remember that I don't know much about computers if you reply! Many thanks.

Hi again - I got SnapMyScreen off w/antimalware software. Many thanks!

Hi there. It's good you solved the problem.

FredMcD said

It’s very sad, but many software downloaders/ installers will trick you into installing not only their program, but other programs as well.

CluelessinCali said

I agree, but how do you use the manual option when the malware has hidden itself?

I was talking about installers. Before giving installers permission to do its install, switch to its Manual option and check Everything out.