For some reason known but to the computer - and certain others - small
(40k or less) attachments are not opening when I double-click on them.
They appear in the attachment line as small, yellow envelopes, along
with a description of size and title.

When I right-click on the logo, the options are minimal: Open, Save
As, etc. If I click Open, nothing happens. If I save it to my H.D.
and try to open it with Word, Excel, Paint, or other programs, there
is no success.

Sounds like the attachments are .msg files. How about upgrading Google Desktop
Search to the latest version, uninstalling it, or telling it not to index
..msg files.

--
-f.h.