I am a fan of Mozilla Firefox because of its features. I am using Firefox since my college days and never shifted to any other browser. But since I upgraded to Firefox 3 and then 3.5, It really slows down at the start up or specially when I type an URL on address bar. My Firefox was running slow and that was frustrating for me. But after digging into folders and files, I finally found the culprit for this problem.
Firefox History Data and Windows History are the reason behind my slow Firefox. When we type some URL on Firefox address bar, it tries to get it from browser history to suggest you related URLs. If you are a power Internet user and browse a huge number of sites on daily basis, You actually stores a huge data in browser history. That history will definitely slows down the really faster Firefox 3 andFirefox 3.5.