If you are going to run a dual-boot system, then, yes, either two hard drives or two partitions are recommended. You didn't mention which operating systems you are using, so I'll make an assumption for an example:
1) Install Windows 95, 98 or ME on the first drive or first partition.
2) Install Windows NT 4.0 or Windows 2000 Professional next on either the 2nd drive or 2nd partition.
3) After the installation of the OS in step #2, you will now have a boot manager that will appear when you turn your PC on. This boot manager will allow you to select which operating system you want to run. Ensure that you install in this order because I'm not sure if the boot manager will get installed if you installed 95, 98 or ME second.
4) If you are using other operating systems which I have not listed, then you might want to look into one of the commercially available boot managers. Also, if you are going to install Linux, it should come with another flavor of boot manager.
5) Now for my input on Ghost. If you are going to make a backup of your disk(s) or partition(s), then you'll have to consider the following:
- Ghost 2001 will allow you to burn your backup immediatly to CDR/CDRW. However, I haven't been able to get this feature to work.
- Earlier Ghost versions allowed you to make a backup of your drive or partition to an image file. When creating the image file, you could specifiy the size of the split so you could later burn the image files to CD. However, when using Ghost to make a backup in this manner, you will need to have a free drive or partition to send the data to because you can't put the backup on the same partition that you are backing up. Once you have made the backup using the 'split' method, you can burn the images to CD and delete them from the drive.