Start Firefox in Safe Mode {web link} While you are in safe mode;

Type about:preferences#advanced<Enter> in the address bar.

Under Advanced, Select General. Look for and turn off Use Hardware Acceleration.

Poke around safe web sites. Are there any problems?

Hi Fred- I tried your suggestion, and both the sites I mention above loaded without issue. But I think hardware acceleration was already off: When I went into the advanced preferences in safe mode, hardware acceleration was unchecked, which, according to the FF guidance I saw on safe mode, is the default in that mode. When I then relaunched FF in normal mode, acceleration was still unchecked. So unless starting in safe mode turned off the acceleration and that setting carried over to normal mode, I'm assuming it wasn't on in the first place. Because the issue only occurs on a few sites, I'm assuming it is sloppy web design as opposed to a browser problem. I wonder if the issue could be related to the problem sites using Java or Flash, or some script that stymies Firefox, but I don't know how to check that. The thing that bothers me is that the browser causes the whole system to hang while it struggles with loading the site. I'm no expert, but I don't think that should happen in a four-core, 2.8 GHz system with 6 GB of RAM. --Eric

Did you try to run Firefox in Safe Mode for a longer period of time?

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem.

• Switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance
• Do NOT click the Reset button on the Safe Mode start window

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

Please give a list of the problem web sites. Some sites don't like Firefox. And something about some sites have given FF problems.

Opps, Sorry, I found them.

Type about:addons<Enter> in the address bar to open your Add-ons Manager. Hot key; <Control>(Mac:<Command>)<Shift> A)

In the Add-ons Manager, on the left, select Extensions. Disable a few add-ons, then Restart Firefox.

Some added toolbar and anti-virus add-ons are known to cause Firefox issues. Disable All of them.

If the problem continues, disable some more (restarting FF). Continue until the problem is gone. After, you know what group is causing the issue. Re-enable the last group ONE AT A TIME (restarting FF) until the problem returns.

Once you think you found the problem, disable that and re-enable all the others, then restart again. Let us know who the suspect is detective.

Hi Fred and cor-el, Thanks to both of you for your time and helpfulness. I have to admit that for the moment, I'm too lazy to do the exhaustive troubleshooting that you are suggesting, as the problem only occurs with the two websites I mentioned, and my first instinct is to blame those sites. From what I have observed of this issue, it would require a system restart at every step to re-create the conditions under which the websites cause FF to bog down. I wish there were a setting in FF to tell it not to hog computer resources when it is stymied by some element of a website. I have been using Firefox for many years, and I don't remember ever seeing it regularly freeze the computer like this before a few months ago.

I've also experienced this issue on a low-spec PC running Windows 7 x64, mostly commonly on my first visit to imgur.com during a session.

The entire OS freezes and any keyboard or mouse input seems during that time will be carried out 20-30 seconds later when everything goes back to normal. Hardware acceleration is off.

charonn0 Wow, you are angry. Just look at that face.  :-)

Follow the instructions above. Any good come out of it?

I've disabled all plugins and addons, but it's hard to say whether it makes any difference since I don't know what triggers it. I will keep them disabled for a while and see what happens.

The freeze is seemingly random, it might happen as soon as I launch Firefox and visit a website or it might happen 6 hours later when I visit that same website again. The only constant is that it only seems to happen once per boot cycle, usually when opening a link in a new tab via middle clicking (but I do that a lot anyway so it might not be relevant.)

charonn0, I'd be curious to know if you encounter your issue on either of the sites I mention in the top post. I have a login on the Comcast site; not sure if that would enter into the equation. As for Facebook, all I notice is that during the freeze-up, the little indicator pop-up in the lower left of the browser window, which for most sites just briefly displays info relating to loading the site, will display the following for a while: waiting for / transferring data from fbstatic-a.akamaihd.net --Eric

Question owner - a standout in your System Details is LogMeIn Rescue Technician Console. Make sure that is not active,

Thanks, Alan. I forgot I'd installed that--is it known to cause problems? Removing it did not help with my issue, but if it's prone to meddling, I'm glad to be rid of it. --Eric

If de-activating didn't help with your problem, by all means keep it if you use it. It just seemed a possibility to me.

FYI, this site just temporarily paralyzed my computer: https://chroniclevitae.com/job_search --Eric

Hmm, no problem with that site.

EricUniqueUsername

Start Firefox in Safe Mode {web Link} by holding down the <Shift (Mac Options) > key, and then starting Firefox. Is the problem still there?

Hi Fred- As I mentioned above, I tried a few things in safe mode when you first suggested it. Just now I did a couple more tests: Restarted in safe mode, tried all three sites

• http://xfinitytv.comcast.net/tv-listings?cmpid=xf_dash_tvl# (the most consistent offender)
• facebook.com
• https://chroniclevitae.com/job_search (the one I posted earlier today)

All three loaded reasonably quickly. I think it was the first time today I'd gone to either Facebook or the Comcast schedule, but I wanted to double check, so I restarted the computer, then l launched FF in safe mode (note: holding Shift key on my Win7 machine while clicking launch button did not start it in safe mode). The Comcast site took at least twenty seconds to load; FB and Vitae loaded normally. So I'm assuming that rules out the problem stemming from an add-on, at least for the Comcast site. Thanks again for your help. --Eric

http://xfinitytv.comcast.net/tv-listings?cmpid=xf_dash_tvl#

The main page displayed in two seconds, and finished in 5 - 7 seconds.

I do not have an account on Face Book.

https://chroniclevitae.com/job_search

This took about 7 - 10 seconds to display

EricUniqueUsername said

(note: holding Shift key on my Win7 machine while clicking launch button did not start it in safe mode)

Did you get some kind of error message? What happen?

No, no error message. FF started in normal mode. Do you have to continue holding the key down for a while after it first starts to launch? Congratulations on not having wasted your time with Facebook...

Start Firefox in Safe Mode {web Link} by holding down the <Shift (Mac Options) > key, and then starting Firefox.

Once you triggered Firefox to start, it should start.

Some problems occurs when your Internet security program was set to trust the previous version of Firefox, but no longer recognizes your updated version as trusted. Now how to fix the problem: To allow Firefox to connect to the Internet again;

• Make sure your Internet security software is up-to-date (i.e. you are running the latest version).
• Remove Firefox from your program's list of trusted or recognized programs. For detailed instructions, see

Configure firewalls so that Firefox can access the Internet. {web link}