Driving me Batty! Help

Have Outlook Express 6. Excel 2002.

When receiving emails with .xls attachements (only all other word etc work
fine) the attachements will not open direct from email. Outlook error
message is:

Cannot find c:\doc & set\User\Local Set\Temp int files\Content. IE5\bunch of
letters and doc name. (Looks like the contnt.IE5 files is missing maybe,
an it be located or replaced? )

You can save attachement and view from saved location, but is a pain in the
butt!

As a test, installed another email program and sent new message with xls
attachement and error message, says antiviris is blocking it. Checked norton
and its all good there!

Any ideas?