Hello,

Try Firefox Safe Mode to see if the problem goes away. Safe Mode is a troubleshooting mode, which disables most add-ons.

(If you're not using it, switch to the Default theme.)

• On Windows you can open Firefox 4.0+ in Safe Mode by holding the Shift key when you open the Firefox desktop or Start menu shortcut.
• On Mac you can open Firefox 4.0+ in Safe Mode by holding the option key while starting Firefox.
• On Linux you can open Firefox 4.0+ in Safe Mode by quitting Firefox and then going to your Terminal and running: firefox -safe-mode (you may need to specify the Firefox installation path e.g. /usr/lib/firefox)
• Or open the Help menu and click on the Restart with Add-ons Disabled... menu item while Firefox is running.

Once you get the pop-up, just select "'Start in Safe Mode"

If the issue is not present in Firefox Safe Mode, your problem is probably caused by an extension, and you need to figure out which one. Please follow the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article for that.

To exit the Firefox Safe Mode, just close Firefox and wait a few seconds before opening Firefox for normal use again.

When you figure out what's causing your issues, please let us know. It might help other users who have the same problem.

Thank you.

I also have this problem!

I have had full system hangs with both 25.0..0 and 25.0.1 including with Firefox safe mode. My system is an Intel Core I7 running Windows 7 Pro. The system locks up tight, often with no mouse pointer displayed. The system does not respond to Ctl-Alt-Del. I have to force a power cycle. When the system has rebooted, I have to resplace sessionstore with a backup copy since it always loses the open tabs. I have also removed and downloaded fresh Adobe Reader and Flash. I removed Shockwave.

Rico 2013 and MikeKier, could you start new threads with troubleshooting info, there is a higher chance of getting a problem solved by doing so.

• Ask a new question: https://support.mozilla.org/en-US/questions/new

I too had the slow, freeze problem with FF 25 (and v25.1) on WinXP SP3. The symptoms were pages taking long time (>20sec) to load, whereas before they came up within 1-2sec. There was no problem with my ISP because I compared the load time for the same site on both FF 25 and Chrome.

I uninstalled FF 25 completed, blew away my profile, reinstalled. Problem still there. I installed FF 24 and the problem still there. I installed FF 23 and the problem mostly disappeared. So now that's what I'm going to use and we'll see.

Had same problems after updating to FF 25. Always hang up and hard reset of pc (P4, 3.4 GHz, 4 GB, W7 Ultimate 32 bit) necessary. Thougth first about OS problems because of restricted user account for web using. But had same problems with admin account. Then looked for hardware problems because of strange W7 hdd failure messages. No change. Also FF safe mode didn't help, hang up also. Then removed FF25 and installed again, added add ons (download helper, ghostery, addblock plus, NoScript). Same problems. Removed FF25 again, reinstalled with add on download helper only. Hand up problems still there. Again removed and reinstalled FF25 without add ons and FF25 works without problems now. For me it's a horror scenario having system hang ups that force me to hard resets caused by FF add ons that won't work after an automatic FF update. An absolutely no go!!! Complete problem solution took one working day!!!! As long as I can't use important (security) add ons for FF this browser is no longer usable and I switch back to IE (security options running without problems). Sorry FF team, I know you're not responsible for add ons but there is need explicit testing of often used add ons before releasing new updates. Otherwise you will make FF a browser that cannot be used anymore because of danger of loss of productivity.

That's horrible. Even without installed add ons FF25 continues to hang up the complete system which forces to hard reset. Now I switch definitely to IE. For the moment this is the better option.

Does not matter if in Safe Mode or not. Takes forever to load a page, hangs to where mouse clicks are unresponsive and slows the whole system to a crawl.

Boy this is bad. Version 25 has been working for me for a week or two at least but today it will not work at all. I am using Internet Explorer 8.0 to reply to these messages (UGH). I hope Mozilla fixes this problem soon and stops blaming we users. I have even tried Safe mode and resetting to default all to no avail.

OOPS my bad. I changed the proxy from one recommended by my company to one I sometimes use when travelling and Firefox works well. Maybe you have another proxy setting you can use.

Sorry Mozilla for blaming you! Now I have some cleanups among my bookmarks and other settings but it should be ok now.

Version 25 installation in Win8 worked fast, reliable and without buffering time for video playback.

I recommend to install another release of Firefox, if safe mode does not help in Win7.

locking this thread

The Owner hasn't returned and Firefox 26 was released two weeks ago - Firefox 25 is "history" now.