I too just purchased a new Dell laptop with Windows 7 Ultimate.
Outlook comes with Microsoft Office Professional 2010. You can download a trial version of Office from the Microsoft web site. I bought Office 2010 with my new laptop so I have Outlook.
I also have Windows XP running as a virtual PC in a window. It has Outlook Express.
You can also download VMware, a virtual machine, and then install Windows XP which has Outlook Express.
By the way. On my new Dell I have Windows 7 Ultimate, Windows XP in a window and Linux in another window. Virtual machines are wonderful.
Bill