Yes, you can do it by adding multiple users where each one has their own .PST file.
Now, the hard part is to actually do it.
Open up Outlook.
Click on Tools, Options then on the Mail Services tab or Mail Delivery tab depending on whether you are using CW or IMO mode respectively. Now click on the button called: Reconfigure Mail Support.
Microsoft have an excellent article on how to switch installation types in Outlook: click here
There is also a good walkthrough of which installation type you should choose: click here;EN-US;195479
A walkthrough on setting up multiple accounts: click here