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!

This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

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

Firefox won't start, profile manager won't start, but firefox.exe shows in processes list (task manager)

more options

Firefox will not start, even though it is listed in my processes in task manager. Can't get profile manager to start either.

I have tried the following to no avail: - try to start FF in Safe Mode, doesn't load - started Windows Vista in Safe Mode, FF still does not load - turned off Kaspersky AV, FF still does not load - uninstalled FF, cleaned out user/####/AppData/Mozilla/Firefox folder, as well as ProgramFiles/Mozilla/Firefox folder, and cleaned our Registry manually from all references to Firefox. Downloaded FF 3.6.3, installed. still does not load - whatever i seem to do, does not fix the problem. When I try to start Firefox, no window appears. I can see the process starting in my task manager. I can "end process" and try to start the program again by double-clicking program icon. Process starts in task manager, but no app window appears.

I am frustrated and have just wasted 2+hours of my night trying to get this to work. Downloaded Google Chrome, unless there is a fix for FF (which I would prefer to use), i will have to switch to Chrome.

I can't pinpoint when this trouble started, but may have been after a recent Windows Update. I already did a System Restore to a restore point about 5 days ago (the oldest one available to me, and I believe that was before the FF trouble started). This has not helped either.

I have run a full virus scan with Kaspersky and a Full scan with Windows Defender. Nothing came up.

Anyone else been able to find a solution to this?

This happened

Every time Firefox opened

Less than a week ago

User Agent

Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US) AppleWebKit/533.4 (KHTML, like Gecko) Chrome/5.0.375.86 Safari/533.4

Firefox will not start, even though it is listed in my processes in task manager. Can't get profile manager to start either. I have tried the following to no avail: - try to start FF in Safe Mode, doesn't load - started Windows Vista in Safe Mode, FF still does not load - turned off Kaspersky AV, FF still does not load - uninstalled FF, cleaned out user/####/AppData/Mozilla/Firefox folder, as well as ProgramFiles/Mozilla/Firefox folder, and cleaned our Registry manually from all references to Firefox. Downloaded FF 3.6.3, installed. still does not load - whatever i seem to do, does not fix the problem. When I try to start Firefox, no window appears. I can see the process starting in my task manager. I can "end process" and try to start the program again by double-clicking program icon. Process starts in task manager, but no app window appears. I am frustrated and have just wasted 2+hours of my night trying to get this to work. Downloaded Google Chrome, unless there is a fix for FF (which I would prefer to use), i will have to switch to Chrome. I can't pinpoint when this trouble started, but may have been after a recent Windows Update. I already did a System Restore to a restore point about 5 days ago (the oldest one available to me, and I believe that was before the FF trouble started). This has not helped either. I have run a full virus scan with Kaspersky and a Full scan with Windows Defender. Nothing came up. Anyone else been able to find a solution to this? == This happened == Every time Firefox opened == Less than a week ago == == User Agent == Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US) AppleWebKit/533.4 (KHTML, like Gecko) Chrome/5.0.375.86 Safari/533.4

All Replies (3)

more options

correction... FF version that I downloaded and installed is 3.6.6 (latest version currently posted). Still does not work for me :(

more options

I am confused that I also have this problem. If you have found a solution email me please. My email is pgg200@gmail.com

Thanks

more options

I found a way to make it work somehow but not really fixing the error... one day when I got really pissed off because FF just won't open, I clicked the icon and killed the enter button, then multiple FF windows appeared. I tried to open it with just a single hit of the enter or double clicking but it won't work anymore, but repeatedly clicking the enter button (mine works with just 3 hits, sometimes 6) seem to open it. And until now, I have no technical explanation for this.