Volume > 2 GB

[Mączka, Mirosław]

>From Microsoft® Win32® Programmer's Reference 

GetDiskFreeSpace
GetDiskFreeSpaceEx

Windows 95: 

The GetDiskFreeSpace function returns incorrect values for volumes that
are larger than 2 gigabytes. The function caps the values stored into
*lpNumberOfFreeClusters and *lpTotalNumberOfClusters so as to never
report volume sizes that are greater than 2 gigabytes.
Even on volumes that are smaller than 2 gigabytes, the values stored
into *lpSectorsPerCluster, *
lpNumberOfFreeClusters, and *lpTotalNumberOfClusters values may be
incorrect. That is because the operating system manipulates the values
so that computations with them yield the correct volume size. 

Windows 95 OSR 2:

The GetDiskFreeSpaceEx function is available on Windows 95 systems
beginning with OEM Service Release 2 (OSR 2). The GetDiskFreeSpaceEx
function returns correct values for all volumes, including those that
are greater than 2 gigabytes.  

mmm