Outlook on the old PC can help. In Outlook 2010, click the File tab, then Info in the left pane. Select Account Settings and then Account Settings again. In Outlook 2007 and older versions, select Tools > Options.
Once there, click the Data Files button. You’ll find the information you need in the resulting dialog box. Or you could click Open File Location to go right to the folder.
Once you’ve installed Outlook onto the new PC, you’ll have a fresh, clean, and empty .pst file. You’ll have to import data from the old file to the new one.
Once Outlook is up and running, click the File tab and select Open & Export > Import/Export. In the resulting Import and Export wizard, select Import from another program or file, then Outlook Data File (.pst).
On the wizard’s next page, for the “File to import’ option, click the Browse button and select the old .pst file. Don’t worry about the other options.
The next page will ask you what to import. If you want to import everything, and I assume you do, just stick with the default.
When you click Finish, the wizard will go away, and the import will start. If you see no visible sign of importing, wait a few seconds; it will start soon enough.
Hope this helps you.