Was the book in a text type file, or an exe program?

Did you already run some malware cleaning programs? Our support article "Troubleshoot Firefox issues caused by malware" lists several programs that can be used "on demand" without interfering with your regular security software. These are free and take considerable time to run. If they finish very quickly and especially if they demand a payment to do the cleaning, you may have a serious infection. Please use the specialized forums listed in the article in that case.

To restore the normal Firefox setup, I suggest:

Clean Reinstall

We use this name, but it's not about removing your settings, it's about making sure the program files are clean (no inconsistent or alien code files). As described below, this process does not disturb your existing settings. Do NOT uninstall Firefox, that's not needed.

(A) Download a fresh installer for Firefox 46.0.1 from https://www.mozilla.org/firefox/all/ to a convenient location. (Scroll down to your preferred language.) For maximum plugin compatibility, choose the 32-bit version, but I think you already are familiar with the 64-bit version.

(B) Exit out of Firefox (if applicable).

(C) Rename the program folder as follows (usually only one of these is applicable to your system):

32-bit install on 64-bit Windows

C:\Program Files (x86)\Mozilla Firefox

to

C:\Program Files (x86)\OldFirefox

All other installations

C:\Program Files\Mozilla Firefox

to

C:\Program Files\OldFirefox

(D) Run the installer you downloaded in step (A). It should automatically connect to your existing settings.

Note: Some plugins may exist only in that OldFirefox folder. If something essential is missing, look in these folders:

• \OldFirefox\Plugins
• \OldFirefox\browser\plugins

Hopefully that will patch up any corrupt files and let Firefox start normally.

Was the book in a text type file, or an exe program?

The harmful file was "HALSetup".

To jscher2000:

Thank you very much. I'll try now.

To jscher2000:

Thanks indeed. Now, I asume i can delete the "old firefox" folder?

Alma7 said

Was the book in a text type file, or an exe program? The harmful file was "HALSetup".

And now i remembered it was also a file with the typical extension .exe Thanks

The only time you should download an EXE is if you know what it does. Some files that are supposed to be text or links or whatever that are sent as exe file Could be malware. Be Very Careful.

Hi Alma7, if you don't notice any important plugins missing, yes, you can delete the OldFirefox folder from your program files folder.

FredMcD said

The only time you should download an EXE is if you know what it does. Some files that are supposed to be text or links or whatever that are sent as exe file Could be malware. Be Very Careful.

I should, Fred. Cheers )

jscher2000 said

Hi Alma7, if you don't notice any important plugins missing, yes, you can delete the OldFirefox folder from your program files folder.

Greatly appreciated! All the best )