Well I use Firefox,
I always prefer Internet Explorer.
May be some of the most dumb things to do.
We all know how Firefox ate away the Mighty IE.
Also who would not agree that Chrome and Opera are the de-facto smart and fast browsers.
So the best practice would be to install all the popular browsers and use them once in a while to see which one is giving the best results.
Also there may be a malware in your OS which is blocking a particular browser, so if you have some urgent work and if you have not already installed few browsers you may have to urgently download a browser which may delay your task at hand.
Also if a browser is not working at a particular time , it is always advisable to opt for a uninstall and a re-install which may restore the vitality of the utility software.
Also always have the latest version of browsers and OS to be on the safe side of the various online threats.