I have an XP Home SP2 computer, DSL connection. I've been using Firefox for quite a while, and just now installed Thunderbird, mostly out of curiosity. It's too early to say if Thunderbird will replace Outlook Express as my default email program. However, one interesting thing I've noticed is that if you have multiple email accounts, they are displayed on the same screen. You don't have to "switch" over to an account to view your messages, as you do with OE. This is much quicker.