Microsoft provides a tool called scanpst.exe. It’s typically in your Office folder so for Outlook 2010 on a 64 bit system
C:\Program Files (x86)\Microsoft Office\Office 14.
On a 32 bit version of windows just use the Program Files instead of Program Files (x86). Navigate to this folder and double-click scanpst.exe.
Once you have your .pst file path in the text area, click Start and follow the instructions.
Locating Your .pst File
Right-click on your mailbox in Outlook and select the Data File Properties… option. In the dialog that appears click the Advanced… button. Your path will be in the resulting dialog (see example below).