This is why you shouldn't open email attachments directly from
the email message. Instead, right-click on the attachment, use
"save as" to save a copy of the attachment to location of your
choice, and open the copy from there.
When you open and save an email attachment directly from the
email message, the file is saved to a temporary folder on your
hard drive. Some email programs retain the contents of the
temporary folder when you close the email application, and other
email programs don't. If you know the name of the file, you can
search your hard drive for it using Windows Explorer or My
Computer (be sure to include hidden and system files and folders
in the search options).
The original file (minus any modifications you may have made) is
still attached to the email message you received.