Outlook 2007 email notification

[High1]

Hello

I have downloaded a .wav file to announce the arrival of new emails, and I have followed this tutorial:

http://www.tech-recipes.com/rx/3510/outlook-2007-use-custom-sounds-to-alert-you-of-new-messages/

The sound email notification does not work after having closed and then reopened the software. I do not have Exchange server; my Outlook works only in the sense that it is linked to my Hotmail/Outlook account.

Does that make any difference?

Thanks

High1