Dell OptiPlex GXa Reference And Installation Manual page 89

NOTE: On systems with hard-disk drives larger than
2 GB, create a primary partition of 2 GB and divide the
remaining capacity into partitions of 2 GB or less. For
example, a system with a 2.5-GB hard-disk drive would
have a primary partition of 2 GB (drive C) and a second
partition of 500 MB (drive D). Hard-disk drives must be
partitioned this way because MS-DOS–based operating
systems (including Windows NT when using a FAT16 file
system) do not support drive partitions larger than 2 GB.
Installing Drives 7-13