If you use Firefox, get Firefox 1.0.1. It includes some important security patches (including a fix that disabled IDN and thus neutralizes the security exploit I wrote about here). It’s a very small download and well worth it.
The release notes say: “Prior to installing Firefox 1.0.1, please ensure that the directory you’ve chosen to install into is clean and doesn’t contain any previous Firefox installations.” How many people do you think will actually read that? I predict most people will simply install over their existing installations.
Ed Bott 
I’ve been wondering lately about Firefox updates and if that’s the one weakness in Firefox that’s going to hold them back from widespread acceptance into the mass, non-technical user audience for now. For those of us who still use “my mom” as the prototype for this user, no, I don’t see ever ever using a browser that requires uninstalling and a clear directory before installing an update or reading directions that require this. If the “automatic update” feature doesn’t make the update 100% transparent to this user, then Firefox will fail to get updates to this type of user and fail to maintain its security lead over IE. Additionally, I’ve been wondering what kind of managed update options there are for corporations who want to use Firefox and have centralized control and administration of Firefox updates on desktop? Anyone know of any resources on that?
Ed, does google ads always serve up an ad for “Sexy Girls & Sexy Guys” on your site? Does “fox” in “FireFox” trigger this or are there some article on your site I’m missing that make this ad in-context? 😉
Jim,
I don’t think you have to actually uninstall Firefox first. I think you can just put it in a clean directory. The user profile data is all neatly separated out in %appdata\Mozilla\Firefox\Profiles.
The Mozilla organization is still working out the update mechanisms. It is a critical point, to be sure.
Oh, and that “sexy singles” Google ad comes up occasionally here as well. It’s not triggered by Firefox, according to the AdSense Preview tool, but I’ll be darned if I know what words are making it appear!
While it’s probably a good idea to install to a fresh folder, I’ve used all manner of broken nightly builds which have often been installed over the top of previous builds and had no problems (though that said I do like to clear the directory and start afresh from time to time). I know others have had issues and that’s probably why the message is there, but short of prompting the user to uninstall the previous copy first there’s no realistic way that they can expect users to do this.
I missed that! Just downloaded & installed & went on my merry way. The updates issue will certainly kick Firefox out of the corporate space as can be seen by the # of companies using tools like SUS, SMS, Altiris, & Shavlik to keep their machines patched. At the minimum, the internal update mechanism should be able to patch inline & if not, the install should recognize and uninstall previous version if needed. I like the quick & painless way that AdAware uses for version updates.
Asa Dotzler, a staff member of the Mozilla Foundation, has this to say on the subject: link
Basically, there’s a known problem with people installing an Installer build of 1.0.1 over a zip build of 1.0. If you used the installer for both or the zip for both it would appear that you are fine.
At the moment Firefox’s auto-update mechanism isn’t showing the update but I remember reading that they are delaying the update notification by a couple of days so that they can handle the load, in the same way the MS did a staged rollout of XP SP2.