Trying to read an Outlook backup on a computer where Outlook isn't available? The article explains how a lightweight viewer can make that easy. You can use this approach to open PST file without Outlook and see all your mailbox content at a glance. The MSOutlookHelp PST Viewer works even with orphaned PST files those that aren't linked to an Outlook profile so old or migrated backups still open without errors. It shows mail items in a clean tree view, and also previews attachments so you don't need extra steps to see linked files.