Why is the HDD limited to 2GB in DOS mode?
Because DOS only supports FAT16 mode that supports hard disks up to a maximum of 2GB. To use a hard disk with larger capacity, FAT32 or NTFS format must be used. Operating systems and their supported FAT sizes are listed as below: DOS 6.22: FAT16 Windows 95: FAT16 Windows 95 ORS: FAT16, FAT32 Windows 98 : FAT16, FAT32 Windows NT 4.