If you have an old pst or an old archive pst and you want to view your old email, you can open it in your Outlook profile.
Do not use File, Import and Export menu, especially if it’s an Archive pst – you may end up with duplicates and will not be able to remove them using Autoarchive (because archive uses the modified date and importing changes the modified date). Just open it in Outlook.
To open a *.pst while Outlook is running:
In Outlook 2010 and older: go to File, Open, Outlook Data File menu and browse to find the pst you want to open.

This screen shot is from Outlook 2003. In older versions of Outlook, browse to File, Open, Personal Folders File.
To add an existing personal data file to your 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.
- Select New Outlook data file and find your existing PST, add it to the profile and set it as the default.
- 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 menu.
- When you return to the Mail Setup dialog, choose Data Files and remove the extra personal folders from your profile.
Note:
- While the New dialog looks like you can only use it to create a new pst, you can select an existing pst file to open.
To remove a data file from Outlook when you are finished using it:
Right click on the top level and choose Close.
Note: You can easily have several pst’s in your profile and only need to close it if you prefer to keep the folder list less cluttered or need to move the file.
Related posts:
« « How to publish Custom Forms in Microsoft OutlookHow to always reply using a different email account » »

Opening old files from outlook like you indicated did not work?
To open a *.pst while Outlook is running:
I followed exactly saw the files but then it gave me this error code
Not compatiable with the current version of pst files… I am using 2002… maybe this file is newer
What version of Outlook created the pst? The new pst format, introduced in Outlook 2003 (and in 2007, 2010) is not usable in Outlook 2002 and older.
I did an upgrade from MS 2007 to MS 2010 and now I have 2 In boxes! And the new one that was created doesn’t have any of my rules. How do I merge them to use my old in box and maintain the use of my rules. Thank you.
What do you do if Outlook says you don’t have permission to open the PST file ?
That usually means the pst is either corrupt or you only have read permissions on the pst file. Check the properties – right click on the pst file and choose properties and verify its not set to read only. If it still fails, run scanpst on it.
good info !!
My computer crashed. I had Windows XP. My new computer is Windows 7. Is there a way to recover my address book and pull it up in Windows 7. I think it would be changing from Outlook express to Microsoft Windows.
Also in what format do you open a .pst file
You had OE on the crashed computer? The address book is in a file called *.wab. Can you access the hard drive from the old computer? It should be at [old drive]:\Documents and Settings\old_username\Application Data\Microsoft\Address Book
I have some .pst files on a flash drive that I am trying to access with Microsoft Outlook. However, when I try to open the files with Microsoft Outlook, I get a message saying “there are no items to show in this view”. Secondly, when I try to import the files, I get a message saying that “the connection to Msft exchange is unavailable. Outlook must be connected or online to complete this action.”
Do you have use an Exchange mailbox? If not, the error message means the profile is not configured correctly. Go to Control panel, Mail and remove the exchange account and add the correct account type.
In the File, Open dialog, select all files (*.*).