Why Mozilla Firefox Lagging ??? -Solved

I'm sure all of Mozilla Firefox user will ask this question because they have experienced this problem especially when they already use Mozilla Firefox for a long time, but the cause of this problem is unidentified. For me, I feel weird because after clearing cache, clearing history, etc, still the problem persist. I tried to uninstall and reinstall my Mozilla Firefox, but still no luck. The lag keep getting worse day by day. So, I've decided to look for answer and solution for this problem.
Below is the explanation on how to solve this problem.

Solution 1 :
1) Clear your Mozilla Firefox Cache.

2) Exit Firefox.

3) Go to your profile folder - Visits this links for guide http://kb.mozillazine.org/Profile_folder_-_Firefox

4) Delete all sessionstore.js

5) Restart Firefox

Solution 2 :

Disable hyperthreading -> right click the Firefox icon click>properties>compatibility>put check mark in compatibility mode box and run in windows 98/windows me mode. This will disable hyperthreading for Firefox on a windows system. (I've tried this method and FYI, I'm using Windows 7 32bit, after I do this step, I can't run Mozilla, I mean when I double click, nothing appear.

Solution 3 :

1. When Firefox is started,launch the Windows Task Manager (press CTRL+ALT+DEL, or right click the clock display on the Windows Taskbar and select Task Manager)
2. Select the process tab
3. Locate and right-click on the Firefox process
4. Select the set affinity option from the popup menu
5. Uncheck CPU 1 and validate with OK.
6. You can go back to Firefox. " 

If none if the above works for you, Read this post :
99.99% Will Fix Mozilla Firefox Not Responding and Freezing Problem