Windows have no controls or title bar after upgrade from 9.10 to 10.04

[R. A. Bilonick]

I tested 10.04 using the livecd before upgrading to 10.04 from 9.10. The
windows looked fine in the live cd. You had borders around the windows
with controls in the upper left for closing and resizing the windows.
You had a title bar that you could grab to move the window, etc. 

After upgrading to 10.04, the default windows are defective. No controls
and no title bar. Plus, the cpu usage now runs at 62% all the time even
when not running any applications. 

If I change the appearance (system|preferences|appearance) and change
"Visual Effects" from "none" to "normal", I get window controls and
title bar, but they are not "embellished" as they should be for 10.04.

Clearly, the gnome window manager or some such software did not upgrade
correctly. How can I fix this? I installed LXDE and the system runs
normally using LXDE (no 62% cpu usage and the window controls etc. are
what you would expect). I've tried re-installing various gnome
components without any improvement.