Win9x and ME systems can only access FAT file systems.
If you dont need ur harddisk to be read by those older OS, then try
to use NTFS. It can give u better usage of disk space, and also
better security.
For example, if u got multi-boot Win98 and WinXP, and u got 2
partitions (1 FAT and 1 NTFS), when u load up Win98 u cant read the
NTFS partition. But u can access both partitions when u load up
WinXP.
Even if u only using one OS, U might wanna consider partitioning
into 2, one for OS and one for data storage. Just in case anything
happen to ur OS and u need to reformat then u only destroy the OS
partition and everything in ur Data partition is safe. Of coz, if u
got 2 HDD then better lah. 