Upgrade Outlook Archive Folders

How we need to Upgrade Outlook Archive ? Outlook is very popular email application and uses ANSI and PST files. ANSI uses in Outlook 97/2000/2002 and Unicode uses in Outlook 2003/2007/2010, ANSI poses 2GB storage capability to store data beyond this limit PST files get corrupts that is why we need to Upgrade Outlook archive and SysTools PST Upgrade software helps us to Upgrade Outlook archive files.