This is the response I got from Lexmark.

Thank you for contacting us regarding this matter. I appreciate the
opportunity to assist you, and I hope my suggestions will provide a
resolution.

The Vista drivers available on the Lexmark website do not contain the
All-In-One Center. They are minimum drivers. Although the scan drivers
are shipped with the web package, they cannot be used by the All-In-One
Center since it is not included. Please use Windows Scanners and
Cameras or Photo Gallery for Scanning.

Please follow the steps given below to perform the WIA scanning:

1. Click on "Start," and "Windows photo gallery."

2. Under "Windows photo gallery" click on "File" and " Import from
camera and scanner."

3. Select the "Lexmark X5150 printer" and click on the import button.

4. To begin the scanning process, click "Scan Now."

If you have any more questions or concerns, please contact me at your
convenience and I will be happy to assist you. (If I am not available,
another representative will reply to you as soon as possible.) To
respond, please select "Reply" in your e-mail software, and be sure that the
past e-mail is included in this reply.

[AOL Users: In order to include the previous e-mail, you must highlight
it with your mouse when you are replying.]

If you need to reply, please be sure to include in your message all
information from prior e-mail messages & replies. If your e-mail client
automatically deletes prior e-mail thread information, it will cause a
delay while we look up your support history. If this is the case you may
want to save the old e-mails as attachments and attach them to the
current e-mail.

Sincerely,
Kumar
Lexmark eSupport Team
http://support.lexmark.com
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