Hi all, I was just working on the FILE_FLAG_NO_BUFFERING stuff again. I''m a little confused about determining the cluster size. According to the MSDN docs, using GetDiskFreeSpace() on disks over 2GB may return incorrect values. Some threads on comp.os.ms-windows.* seem to support this as well. I did come across this, however: http://www.codeguru.com/Cpp/W-P/system/article.php/c2885/ On the other hand, it doesn''t seem many people are using this, instead relying on GetDiskFreeSpace() regardless of disk size. Thoughts? Dan