Because an ANSI PST file is an old PST file and stores only about 2 GB of data in it, and because ANSI PST files are not supported in newer versions, they have to be converted to Unicode PST files. Use the Softaken ANSI to Unicode converter Tool to convert ANSI PST files to Unicode PST files. This is the most secure and best application. It quickly converts multiple ANSI PST files to Unicode PST files. This application works on all Windows OS versions. It creates Unicode PST files of unlimited size. This application is user-friendly.