suppose use PowerQuest PartitionMagic for partitioning, is it better to have one more primary partition for multiple OS? if you use NTFS feature for all the partitions, cant reboot from floppy disk when system corrupsted?
which one is better, NTFS or FAT, to make the best use of your HDD?
Thanks for your advise!

suppose use PowerQuest PartitionMagic for partitioning, is it better to have one more primary partition for multiple OS?
>>>One more primary partition??????????可能吗？有不少软件允许在同一分区安装多个OS。比如Acronis OS Selector。不过我没用过。如果你的配置不错，可以考虑安装Virtual PC。

if you use NTFS feature for all the partitions, cant reboot from floppy disk when system corrupsted?
>>>可以用它启动，但是不能浏览任何分区。既然系统垮了，就得重装。有了系统安装盘，要软盘干什么？

which one is better, NTFS or FAT, to make the best use of your HDD?
>>>自然是NTFS。安全性好，而且更有效的利用空间。