First of all run the Outlook as administrator at your new computer (right click to the Outlook shortcut, then choose menu Run as administratr and enter the proper password if it will be prompted. Then go to menu File > Open > Open Outlook Data File... and select your PST file. It should open it correctly.

In there is still a problem, you may need to recover your PST file. In some cases of damages it may start to prompt the password to open even it was not set.