EDIT: Actually it is not documented in MSDN but in the Microsoft Knowledge Base (http://support.microsoft.com/kb/78346/en). While that article says that even some Microsoft tools cannot handle files larger than 32K, I just expanded the buffer to 64K in my latest COMMIT to reflect the official size limit documented in that article. So JNA now can handle larger files than Windows itself! ;-) Also I added code comments so other authors can see where the numbers are taken from. :-)