Join the AMA (Ask Me Anything) with the Firefox leadership team to celebrate Firefox 20th anniversary and discuss Firefox’s future on Mozilla Connect. Mark your calendar on Thursday, November 14, 18:00 - 20:00 UTC!

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Why is firefox 39.0.3 not installing the firefox.exe file during the installation or upgrade?

more options

I had firefox 39.0 on my computer. It said the update to 39.0.3 was available. I installed the update and now the firefox icon says it can't find the firefox.exe file when I try to start the program. I have uninstalled the program and downloaded 39.0.3 from your ftp server. I then installed the program and the same thing happens. I checked in the c:\Program files (x86)\Mozilla Firefox\ folder and firefox.exe isn't in the folder. I have been using firefox as my daily web browser and now I am having to use something else to do my work.

I had firefox 39.0 on my computer. It said the update to 39.0.3 was available. I installed the update and now the firefox icon says it can't find the firefox.exe file when I try to start the program. I have uninstalled the program and downloaded 39.0.3 from your ftp server. I then installed the program and the same thing happens. I checked in the c:\Program files (x86)\Mozilla Firefox\ folder and firefox.exe isn't in the folder. I have been using firefox as my daily web browser and now I am having to use something else to do my work.

All Replies (2)

more options

hi wjcoats, please try to right-click the installer and run it with administrator privileges...

more options

That got the installation completed.

Why did the upgrade fail? This all started when Firefox 39.0 said I had an upgrade to 39.0.3 and asked me to restart. I restarted and the Firefox.exe file was missing from the folder.