How to repair broken Delpi XE3 IDE after installat

I have created a new package with one component in it (descendant of TSpeedButton), compiled the package and installed it in the IDE (Delphi XE3 Pro).
It worked as far as I have tested it (I could use my component in design- and runtime).

BUT: I have closed the IDE and now I can't start it.
It displays the splashscreen and shows progress:

Documentation Insight Express
CodeSite Express
Jedi Code Library
Jedi Visual Component Library

Up to All designtime packages loaded (translated from German, YMMV).
I guessed it was my package, so I deleted the BPL. On next start, Delphi said it could find the package and asked if it should load it when loading the next project; I clicked "No".
But still Delphi doesn't start, behaviour is exactly the same. Splashscreen loading and STOP.

The "Repair" option of the installer didn't help, either.

Pharaoh

Edit: It turns out I was too impatient - A reboot cleaned it up.
I still marked the answer of Ken White because it would have been the solution of the last resort.

Create a new desktop shortcut for Delphi, modify it's properties (right-click and choose Properties), and add -rFoo to the end of the command line. Then start the IDE from that new shortcut.

This creates a new, empty Delphi registry branch that contains only the default components and settings (called foo). It will not load any of your component packages (or any third-party ones you've installed that weren't part of the normal installer). You can then add back any third-party packages one at a time. Just continue to run the IDE from your new shortcut, and you should be fine.

If this doesn't put you in a state where you can run the IDE, you've somehow totally borked your install, and you should uninstall completely and start over from scratch.