I was searching for some extensions and plugins on http://www.mozilla.org and found some of them irresistable. Without any second thought installed them and gave my firefox a restart. One of the plugin was IE tab in firefox which enabled a developer to view a link in IE as a tab embedded in Firefox. As i restarted my firefox a pop up said “IE tab extension installed. Please restart your firefox”. That was it!!
I never could start my firefox again and to my horror all my bookmarks and RSS feeds were still lying in it. The only worse option i had was to reinstall firefox with a slight hint of hope that at least the bookmarks would not get removed. But to my utter dissapointment it gave the same popup even on a reinstall.
Finally I had to delete manually all the data from my %APPDATA% related to firefox and that was the end of them. So much to my temptations!!