Use existing data file as the delivery location

Outlook 2003 and older

The steps and screenshots for Outlook 2003 and older are pretty much the same, with just minor differences.

To use your existing personal data store with your new profile:

If you just created your profile and have the Profile dialog open, skip to Step 3 after clicking Finish in the profile wizard.

Open Control Panel and find the Mail applet. If you use the Category view in Windows XP's Control Panel, look for the Mail applet in the User Accounts category.
Select the Show Profiles button.
Select your new profile from the Mail dialog and choose Properties, then Email Accounts and finally, View or change email accounts.

Click the New Outlook data file button near the bottom of the dialog.Even though this dialog appears to be only for creating new personal data stores (PST) you can use it to browse for an existing PST.
Click Ok on the New Outlook Data File menu, leaving the default selection selected.Tip: If you are going to create a new PST in Outlook 2003 and need to use it with older versions of Outlook, select Outlook 97/2002 format, otherwise, use the default PST format that is selected.

Browse to find your existing PST and select it, then press OK to add it to the profile.

To set your existing PST as the default delivery location, Ok your way back to the Email Accounts dialog and select the PST you just added in the Deliver new e-mail to the following location dropdown. Then press Finish. If Outlook is open, when you press Finish you'll be reminded that this won't take effect until you close and reopen Outlook.

To remove the PST from your profile, when you return to the Mail Setup dialog, choose Data Files. Tip: If you have mail in the pst you want to remove you can use File, Import. Because you probably don't have any custom views in this pst, Importing the contents works fine.
If you decide to leave it in the profile, you can right click on it in Outlook's folder list and choose Close to remove it later or return to this screen at any time and remove the data store.

Select the data store you wish to remove from your profile and click Remove.The data store is removed from your profile, but not deleted from your hard disk.