Cannot open user preferences menu anymore I'm getting some error and cannot open my User Preferences window anymore.

I was doing some Python addon development (nothing fancy, just iterating through objects), loading and unloading my addon and at some point I must have killed the User Preferences window.  Now when I try to open it by selecting File > User Preferences, a popup displays "Failed to open window!".  The console displays:

Win32 Error# (3221692624): &lt;no system message&gt;


I've tried restarting my computer, but that didn't help.  I've also tried deleting my script from C:\Users\&amp;lt;user&amp;gt;\AppData\Roaming\Blender Foundation\Blender\2.78\scripts\addons.

What can I do to restore my User Preferences window?
Okay, I just did a full uninstall followed by a reinstall and toasting my Blender user directory.  The User Preferences will open now.