SysTools PST Upgrade - Version 2.0 Need to convert Outlook ANSI PST to Outlook Unicode PST file? We are here to solve your such types of problem. We offer you the highly advance SysTools PST Upgrade software that helps users to transfer Outlook ANSI PST to Unicode PST and vice versa. Microsoft Outlook 2003 and Microsoft Outlook 2007 have a larger overall size limit 20 gigabytes (GB) for the personal folders (.pst) file than the .pst files that are in the earlier versions of Microsoft Outlook such as Microsoft Outlook 2000 & XP. In Outlook 2002 and earlier the .pst files are in the American National Standards Institute (ANSI) format, and the overall size has a limit of 2 gigabytes (GB) only. Unicode PST file has the overall size limit of 20 GB. Just to avoid corruption due to exceeding the size limit of 2 GB imposed on ANSI PST file, you need to convert your ANSI PST file to Unicode PST file to enhance the size limit to 20 GB. Our PST Upgrade Tool easily & successfully converts with high conversion result Outlook 2000 to Outlook 2003 in few clicks. Software supports to convert the entire email