So everything on your computer is running slower? I would try then contacting your ISP to see if there is a network connection issue. Or, Download and Install MalwareBytes Anti-Malware, run a full Scan. http://www.malwarebytes.org/. This helps check that there are no viruses on your computer causing issues. You can uninstall this program after you clean off any infections.

Try to boot the computer in Windows Safe mode with network support (press F8 on the boot screen) as a test to see if that works.

Thank you for your response. :~) I tried rebooting in Safe Mode w/networking - no effect.

MS Essentials is updated and reports no malicious software.

Other OS' on various devices work correctly on the same router.

Firefox, IE, and Thunderbird *boot* quickly, but communication within them seems to be the problem.

What is the CPU load when this happens?

My problem is just with Firefox 14 and Flash. IE works perfectly. Flash in FF has been messed up in all of the latest builds. So either it is a FF problem or an Adobe problem...period!!!

CPU load on processor 0 is <3%, with the other processors parked.

Update - Now that I'm back from vacation and on my home domain (Cox Comm), everything works normally. I suspect some sort of security certificate was needed and the system or browser wasn't updated properly. I don't really know much about them, so I'm just guessing.

Hello, I seem to be having this issue currently. It just started recently, and seemingly out of nowhere. I'm an IT pro and there's no eerie things going on in the network, in the dll handles, not in any place I can find is there a problem... But firefox still runs "choppy" while scrolling through, or viewing other tabs/pages. I have even attempted the "Don't load tabs until I select them" fix, to no avail.

My computer is absolutely secure, with ESET Smart Security 5 business installed and running smoothly. Any new software is always loaded sandboxed so there are no chances of malware or viruses being the culprit. My guess is a plugin/extension compatibility issue, but I can't be sure and can't seem to single out which plugin, if any (maybe a combo?) are to blame.

Any guesses?...

The Reset Firefox feature can fix many issues by restoring Firefox to its factory default state while saving your essential information. Note: This will cause you to lose any Extensions, Open websites, and some Preferences.

To Reset Firefox do the following:

1. Go to Firefox > Help > Troubleshooting Information.
2. Click the "Reset Firefox" button.
3. Firefox will close and reset. After Firefox is done, it will show a window with the information that is imported. Click Finish.
4. Firefox will open with all factory defaults applied.

Further information can be found in the Refresh Firefox - reset add-ons and settings article.

Did this fix your problems? Please report back to us!

That's about a Microsoft reply!!!! I did Reset Firefox and it didn't work. This is not just on one computer either, FF or Flash is messing up on several computers!!!!!

I also have this problem with 14.0.1. All was ok until earlier in the week. Chrome is probably 10x faster right now. I ran my antivirus, etc. and all is ok. Seems like the worst is when logging into a site that requires authentication. Something seems to point to Firefox!

More than likely it's the plugin container, Flash or both!!!

The above described problems have not disappeared on my computers nor on my father’s computer. Firefox version we are using is 14.0.1. There is an optical fibre coming to my house and connection speed is 100 Mbps. Thus, the drop in perceived speed is huge. Firefox slows down also Internet Explorer, but these problems disappear once you close Firefox. I couldn’t find any fixes that would have worked and was forced to start using other browsers.

I have Win7 Home premium and FF 15.0.1 Lately,I find that FF hangs for almost a full minute when I click on my Webmail Notifier app,and FF itself takes about 45 seconds to launch.The cursor still moves,but doesn't do anything.BTW,I always have the browser running in Sandboxie,and the interesting thing is this doesn't happen in an unsandboxed iteration of FF.I will post this on the Sandboxie forum as well-maybe it's not a FF issue.

Solved! It was the McAfee Site Advisor plug-in! God,I hate Mcafee! Ever since my ISP dumped F-Secure for McAfee,I have had headaches.Never had a problem with F-Secure.

Hey everyone, just wanted to let you know I found a solution to the problem that I was experiencing. There's a program we use which main functionality is through the use of java.exe Or javaw.exe. Whenever we seem to use the process it causes this extreme 'lag' to happen with firefox. For now we just use the processes during separate times :/

"Hey everyone, just wanted to let you know I found a solution to the problem that I was experiencing. There's a program we use which main functionality is through the use of java.exe Or javaw.exe. Whenever we seem to use the process it causes this extreme 'lag' to happen with firefox. For now we just use the processes during separate times :/ "

Well,between our two solutions,we have no doubt helped quite a few people!