I cannot open firefox browser. I get 'Cannot load XPCOM. cannot access to 'reset'
I cannot open my mozilla Firefox browser. I get a notice 'Unable to load XPCOM' this prevents me from using the firefox reset button. I cannot delet or uninstall firefox browser for the same reason. i am Running the browser on windows Vista.
Uninstall your current Firefox version, if possible, to cleanup the Windows registry and settings in security software.
Do NOT remove personal data when you uninstall your current Firefox version, because all profile folders will be removed and you lose personal data like bookmarks and passwords from profiles of other Firefox versions.
Remove the Firefox program folder before installing that newly downloaded copy of the Firefox installer.
(32 bit Windows) "C:\Program Files\Mozilla Firefox\"
(64 bit Windows) "C:\Program Files (x86)\Mozilla Firefox\"
It is important to delete the Firefox program folder to remove all the files and make sure that there are no problems with files that were leftover after uninstalling.
Your bookmarks and other personal data are stored in the Firefox profile folder and won't be affected by an uninstall and (re)install, but make sure that "remove personal data" is NOT selected when you uninstall Firefox.
If you keep having problems then also create a new profile.