I have been using Firefox for years now but it has not been working good lately. It gets really slow. As usual, with the help of Google I found the solution.
1) As suggested, I installed Speedyfox. As soon as you get the app running, it will pop a window up that looks like this:
2) Then, I did the usual defragmentation which I haven’t done for quite a while now.
3) Uninstalled the existing Firefox and reinstalled the latest version.
It’s now working well and almost back to its normal speed but I’m considering of switching to Chrome soon.