Check step by step procedure to merge PST file into single PST file
Step 1: Download, install and run PST Merge Software.
Step 2: Click on the Add file option to select multiple PST files.
Step 3: Click on Add Folder option to select a particular folder to merge.
Step 4: After selecting a file or folder you have an option Remove particular file or clear all.
Step 5: Click on the Preview PST File option to check the preview of the PST file with attachment.
Step 6: Choose the merge option such as:
Step 7: Select the checkbox to Remove Duplicate Items.
Step 8: Select the option 'Merge into created new PST file', and then you can create a new folder to save the PST file and also save in an existing folder.
Step 9: Choose the option 'Merge into existing Outlook PST file' you can save your file into existing PST file or also save into Outlook.
Step 10: Click on the Merge PST button to start the merging process.