Outlook users mostly come across the problem of how to partition PST file. As they are not aware about the actual reason & facts lying behind an oversized PST file. Actually MS Outlook use a PST file to save all the data of different Outlook items. Earlier versions of MS Outlook like Outlook 97, 98, 200, and 2002 uses ANSI file format which has a rigid storage limit of 2GB & newer versions of MS Outlook like Outlook 2003, 2007 and 2010 follows Unicode file format which has a size limit of 4GB. Once the size PST file reaches these set limit it starts affecting the working of Outlook by making its data difficult to access & sometimes corrupt it. So, the best way to come of this situation is split PST files. For which you can use SysTools partition PST tool to partition bulky PST file. With Split PST software users can break their PST file into Four different ways like: