1) By default, Outlook .pst files are hidden files. On Windows XP, they are usually located in the C:\Documents and settings\\Local Settings\Application Data\Microsoft\Outlook folder.
2) On Windows Vista, and Windows 7, Outlook files are usually located in C:\Users\\App Data\Local\Microsoft\Outlook folder.
If you want to make hidden files and folders visible. You can do that in Windows Explorer: 1) Right Click on Start/ Go to Explore 2) Click Tools/ Folder Options (If menu bar is not visible, press ALT-T to bring it up) 3) Click on the View Tab 4) Select "Show Hidden Fles" 5) Uncheck Hide empty... and the 2 options below
You will now see the folders under Documents and Settings or APP DATA in Windows 7