I use Win XP. When Windows Explorer is opened, the pane on
the left side shows the various hardware and directories.
Whatever item has a subset at a lower level has a plus (+)
sign on the left side. Clicking on the plus sign will
Expand the item and show all sub-items. My problem is
this.

For Local Disk (C:) only, I have lost the plus sign.
Everything else in the pane has the appropriate plus sign
and clicking on it will expand the lower levels. However,
for Local Disk (C:), clicking on it does nothing. Right
clicking shows the "Expand" greyed out. The directories do
show up in the right pane, but I would like to have the
expansion capability for the Local Disk (C:) in the left
pane. I can't recall anything that I did to cause this
problem which started about 2 weeks ago. I have tried to
Reset Folders in Tools/Folder Options/View, followed
by "Apply to all folders", but this did not help.

Does anyone know how I can restore this capablility
without resorting to a previous "Restore Point". Thanks in
advance for whatever help you can suggest.