If set to yes, the disk spanning feature will be enabled. Instead of storing all the compressed file data inside SETUP.EXE, the compiler will split it into multiple SETUP-*.BIN files -- known as "slices" -- suitable for copying onto separate floppy disks, CD-ROMs, or DVD-ROMs. Each generated slice contains a number in its name which indicates the disk onto which it should be copied. (For example, SETUP-2.BIN should be placed on disk 2.) The generated SETUP.EXE always goes on disk 1 along with the SETUP-1*.BIN file.

The size of each slice and the number of slices to create for each disk are determined by the values of the DiskSliceSize and SlicesPerDisk [Setup] section directives, respectively. Other disk spanning-related directives that you may want to tweak include DiskClusterSize and ReserveBytes.

Note that it is required that you set this directive to yes if the compressed size of your installation exceeds 2,100,000,000 bytes, even if you don't intend to place the installation onto multiple disks. (The installation will still function correctly if all the SETUP-*.BIN files are placed on the same disk.)