Upgrade to v4 in Windows 7 64 bit - very slow, hangs, etc.
I upgraded from v3.6 to 4. Uninstalled previous version and fresh installed 4. Now, FF hangs up for at least 60 seconds loading websites...fine in IE. Once a page loads, it hangs (spinning circle) if I click on anything on the page. Wait is for "data transfer".
Tried all the suggestions in Support and nothing works.
Wšě wotmołwy (3)
I have the same problem on two separate machines both W7 64 Bit. I can't believe this isn't a wide-spread problem. Tried everything recommended herein. The only things that fixed this was uninstalling and reverting back to 3.6. Sorry Mozilla this is a bad one.
I had tried some links I found on internet.
What worked finally was to disable all add-ons using Help --> Restart with add-ons Disabled. With this way I verified with all the add-ons disabled there was on performance problem (like my second machine with Windows 7 32 bit).
After that, I started to enable the add-ons starting from the more important for me. It still worked with no problem. I left disabled some non-important for me.
I am not sure whether the problem was from those that I left out or whether the whole process "corrected or reset" something. The result is the same. Firefox 4 in Win7 64 works like in Win7 32.
Billw1948 - Win7x64 Fx4.0.1 works beautifully for me. You could start by getting rid of your Ask toolbar.
Then I would recommend you work your way through this(Safe Mode, Problematic extensions etc) -
https://support.mozilla.com/en-US/kb/Troubleshooting%20extensions%20and%20themes