Just plopping down a PST file is the worst possible way to "configure"
Outlook.
You must configure Outlook expressly to use a different PST file. And don't
export a PST. Just copy and reuse it.
Start over with a new profile and configure it with the one and only PST
file you want to use.

To use another PST file (such as one from an earlier installation) and set
it to be the default for your current installation of Outlook, you will
first need to know the location and name of the PST file you'd like to use
as your new default. Then use the following directions:
- Go to Tools > Options > Mail Setup > Data Files > Add...
- Add the PST you'd like as your new default, then Close > OK to exit the
Options dialog
- Go to Tools > E-mail Accounts > View or change existing e-mail accounts
- Select the PST you just added in the "Deliver New e-mail to the following
location" dropdown (it will most likely appear just below the current
default Personal Folders file) > Finish
- Exit and Restart Outlook
- You can now close the previous default PST (R-click on that pst folder
while in Folder View and select "Close <foldername> Folders"). If you have
any information in your former PST that you'd like to transfer to your new
default PST, you can drag and drop from one to the other before you close
the old one.