I have a cuestion. How Can I to add other hard disk to my computer? I need to configurate anyone?

What O/S you running now? Also was hardware platform?

If you already have one (just one) hdd, you don't have to something configurate, if all hard disks are formated.

the one alreadt existing would be ur primary IDE-0
and now add up with new hard disk that would be ur secondary IDE-1

u neednt configure anything, just look for the jumpers specification while connecting and the IDE cable that u do connect.

You'll need to add more information to your post.
Once you add the hard drive to the machine, you will need to format it.
If you plan to use the hard drive under MS Windows, then you will need to format it with either FAT32 or NTFS.
If you plan to use it under GNU/Linux, then there are many filesystems you can format the drive to, (ext2, ext3, ReiserFS, XFS, JFS), this is why you need to specify what you plan to use the hard drive for.

If you use it under MS Windows, once you format the drive, it should be ready to be used under the system.
If using the Hard drive under GNU/Linux, then after you format it, you'll need to make some changes to the /etc/fstab, to mount the drive during boot time.