@tical2399: people who proclaim themselves "tech savvy" are usually egotists who think that, since they've edited one registry key one day, they're above the rest of the population - and usually, when I'm called in to fix some computer after a tech savvy guy went over it, they've made such a mess with settings, default applications, even hardware parameters, that it's faster to start from scratch.
If Fx 4 crashes after updating, you must do a few things:
- backup all bookmarks, security certificates etc. somewhere
- uninstall the browser, all extensions and plugins, and delete user profiles
- clean up the computer (remove crapware, clean up the disk, do a registry check) and update it (Windows Update: apply all security and driver updates, including SP2 - Vista - or SP1 - Win7 - and IE9, which comes with critical Direct2D fixes)
- reinstall Fx4 and import back settings.
- there is a known bug with Java; ensure you don't have Java installed, or that you have the latest version, and disable the plugin in Firefox if you don't have use for it.
- get the latest Flash plugin (10.2.503.1).
If it still crashes THEN, you should open a bug report to Mozilla.