This tutorial will explain where to find your outlook.pst file in windows 7
To see AppData, enable viewing of hidden files and folders in Control Panel > Folder Options > View
Another (quicker) way to view hidden files is to press Alt when you have an explorer window open. This will bring up the standard File / Edit / View / Tools / Help bar. Under Tools, click Folder Options. Pressing Alt also works with the defaulted hidden menu bars of Windows Mail, Word 2010, etc.