Outlook 2007: cannot create a new pst file

[Dan2]

I want to create a new .pst file.

In accordance with Outlook Help:

1. I click File | Data File Management |
2. The Account Settings box pops up
3. I click Data Files | Add
4. In New Outlook Data File box I select Office Outlook Personal Folders File (.pst) and click OK
5. In Create or Open Outlook Data File, in File Name I enter the name of a new file and click OK
6. The box Microsoft Office Outlook pops up with the message "The requested operation failed". No reason is given.

In step 5 the Help file mentions the box "Create Outlook Data File" (without Open) with Name and Password fields.

Thank you for your help.
Dan