I've been using Firefox and Thunderbird (Outlook equivalent) for a good while now and must say have been really impressed by the quality of this free software. However, as others have stated if you don't like it, its just a case of uninstalling and reverting back to IE.
The only "problem" I've had is with the Windows Update website. This appears to require the use of IE so I've kept IE on my PC but only use it for accessing that site.
Yes, Win Update does require IE. So much so that even Opera - when set to identify itself as IE - will not fool it. There is a tweak that allows access from Firefox, but it's unreliable and frankly totally unnecessary.
Cheers Folks, i have downloaded both firefox and thunderbird and i must say i am impressed, but when ever i use thunderbird it repeatitly asks me for my isp password and after about five tries it tells me that i am enterimg an invalid user name or password, i know the password i am entering is correct any suggestions.