What would major reason be for inability to open attachments such as
jpgs?  Windows XP, IE v. 6...desktop DELL about a year old.

To stop automatic blocking, do the following:



On the Tools menu, click Options, and then click the Security tab. 
Under Download Pictures, click Change Automatic Download Settings. 
Clear the Don't download pictures or other content automatically in
HTML e-mail check box.

You mean in outlook?

Happens with most emails especially pictures and files.