Since is already uninstalled. Then Delete the Mozilla Firefox Folders in C:\Program Files and C:\Program Files(x86) Then restart system. Then run Windows Disk Cleanup. Then run it again and click the button that says Cleanup System Files. Reinstall with Current Release Firefox 57.0 with a Full Version Installer https://www.mozilla.org/firefox/all/

Note if not installed .... Profile is saved, and it maybe corrupted which could be a reason not starting up. https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data and https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile and https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles and https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles if need help rescuing ...................

Please let us know if this solved your issue or if need further assistance.

If you are not getting any kind of crash dialog, either from Windows or from Firefox (Mozilla Crash Reporter), Windows may be "killing" Firefox early in the startup for some reason. Perhaps...

A Recent Issue for 64-bit Windows Users with 64-bit Firefox

One of the main effects of the Firefox 56.0.1 update was to switch 64-bit Windows users from the traditional 32-bit version of Firefox to the 64-bit version. We received a number of puzzling reports of Firefox either not starting (probably due to incompatibilities with 64-bit drivers that Firefox expects/requires) or not loading any pages after this migration.

One user discovered that Windows was silently killing Firefox at startup and recording it in the Windows event logs (you can view event logs using the Event Viewer). Based on one of the reports in the log, we were able to trace that to an out-of-date Logitech camera driver, of all things. Five other users reported that uninstalling the Logitech camera resolved their problem as well.

• https://support.mozilla.org/questions/1179822#answer-1019375
• https://support.mozilla.org/questions/1181740#answer-1021470
• https://support.mozilla.org/questions/1181405#answer-1022798
• https://support.mozilla.org/questions/1182572#answer-1023413
• https://support.mozilla.org/questions/1182847#answer-1024290
• With 57: https://support.mozilla.org/questions/1188971

Do you want some assistance in looking at event logs, or do you have such a camera?

If the investigation doesn't yield any solutions, it is worth trying a return to 32-bit Firefox.

While normally this kind of change is seamless -- the installer detects your existing data and preserves everything -- you might want to make a backup "just in case."

• Back up and restore information in Firefox profiles
• How to opt out of 32-bit Firefox migration to 64-bit

Note: If you decide to try 64-bit Firefox on the same system at some point in the future, see: How to switch from 32-bit to 64-bit Firefox.