Last week we told you how Mozilla would soon be pushing Firefox 3 onto the Firefox 2 users who have yet to upgrade. Well, that day is today. If you’re still running Firefox 2 you should see the update prompt in the next day or so when your browser checks to see if a new version is available.

You can, of course, choose not to upgrade. The prompt you’ll receive will give you options to update later, never, or at that very moment. If you have any extensions that won’t work in the new version you should see a notification similar to this:

firefox 3 upgrade.png

If you choose not to upgrade it’s important to know that come December Mozilla will stop supporting Firefox 2. At that time they won’t be releasing any security or stability patches, which could leave you vulnerable to outside attacks. By that time most users will have probably transitioned over to the new version though.

Mozilla has created a guide that walks you through the steps in the upgrade process.