Cannot get a populated Windows Explorer window

Hi --

I have a Windows XP Pro (SP3) computer that will not display a properly
populated Windows Explorer window.

If I open Windows Explorer, the left pane populates with

Desktop
My Documents
My Computer
My Network Places
Recycle Bin

The Address bar reads "My Computer" and the right pane shows the searching
flashlight icon forever.

I can click on My Documents and be taken there. But if I hover over the left
pane, I get an hourglass icon.

If I click on My Computer, I don't get much of anything, except for an
eventual "(Not Responding)" in the title bar. Then I have to kill Explorer.

I can enter a drive letter or path in the Address bar and be taken there.
But if I hover over the left pane, I get an hourglass icon.

"Automatically search for network folders and printers" is switched off on
this PC.

What could be causing this, and how do I fix it?

Thanks,
CL