When you FORMMAT a Hard Drive and give it 2. Partitions the first Partition has win xp on it so that would be called the Primary Partition and the other Partition would be called the Secondary Partition right???

So what is a Logical Drive is that when you give a Hard Drive One Partition and the whole Drive is used is that a Logical Drive??AnyoneEach partition becomes a logical drive. In a typical system, the primary partition would be the one with the OS files on it, though most modern OSes can actually handle multiple primary partitions. The important thing is that your "main" partition (which must be primary) also has to be active in order to boot the computer.
Drive 0 in disk management utility is a "physical" drive. Drive c:\ is a logical drive, which can be a single partition, or span multiple partitions and even multiple physical disks, which brings you beyond partitioning, and into dynamic disks.
What did you meen when you told me that Disk 0. is the Pysical Drive and Drive C: is the Logical Drive??

The Hard Drive with win xp is Drive 0. the Physical Drive and Drive C: is still Drive 0.

If you have WIN XP on Drive 0.  and you only have one Partition then Drive C: is also the Physical Drive to right?

Logical Drives would only be Drives that you keep Partitioning RIGHT??

Please helpYou are correct.

"Logical" drives are ways of labeling partitions on physical drives. 

For example, I have two physical drives in my computer, but the larger drive is split into two partitions.  The operating system (XP) reports three logical drives.

c:  (on which the operating system resides.)
d:  (the second small hard drive.)
e:  (the second partition of the first physical drive.)

I will have to find information for you to explain the hierarchy of how the operating system assigns letters to drives and partitions.

The article below illustrates drive identification schemes under different operating systems, but the part I quoted is the basics of how DOS/Windows decides things.

http://www.answers.com/topic/c-6?cat=technology

Quote

Order of assignment

Except for CP/M and early versions of MS-DOS, each of these operating systems assigns drive letters according to the following algorithm:

   1. Assign the drive letter A: to the first floppy disk drive (drive 0), and B: to the second floppy disk drive (drive 1), if present.
   2. Assign a drive letter, beginning with C: to the first active primary partition recognised upon the first physical hard disk.
   3. Assign subsequent drive letters to the first primary partition upon each successive physical hard disk drive, if present within the system.
   4. Assign subsequent drive letters to every recognised logical partition, beginning with the first hard drive and proceeding through successive physical hard disk drives, if present within the system.
   5. Assign subsequent drive letters to any RAM Disk.
   6. Assign subsequent drive letters to any additional floppy or optical disc drives.

MS-DOS versions 3 and earlier assign letters to all of the floppy drives before considering hard drives, so a system with four floppy drives would call the first hard drive E:.

The order can depend on whether a given disk is managed by a boot-time driver or by a dynamically loaded driver. For example, if the second or third hard disk is of SCSI type and on MS-DOS requires drivers loaded through the CONFIG.SYS file (e.g. the controller card does not offer on-board BIOS or using this BIOS is not practical), then the first SCSI primary partition will appear after all the IDE partitions on MS-DOS. Therefore MS-DOS and, for example, OS/2 could have different drive letters, as OS/2 loads the SCSI driver earlier. A solution was not to use primary partitions on such hard disks.

In Windows NT, Windows 2000, Windows XP and OS/2, the operating system uses the aforementioned algorithm to automatically assign letters to floppy disk drives, optical disc drives, the boot disk, and other recognised volumes that are not otherwise created by an administrator within the operating system. Volumes that are created within the operating system are manually specified, and some of the automatic drive letters can be changed. Unrecognised volumes are not assigned letters, and are usually left untouched by the operating system.

A common problem that occurs with the drive letter assignment is that the letter assigned to a network drive can interfere with the letter of a LOCAL VOLUME (like a newly installed CD/DVD drive or a USB stick). For example, if the last local drive is drive D: and we have assigned to a network drive as E:, then when we connect a USB mass STORAGE device it will also be assigned drive E: causing loss of connectivity with either the network share or the USB device. To overcome this problem we have to manually assign drive letters or to install a third-party software such as USB Drive Letter Manager.

Another condition that can cause problems on Windows XP is when there are network drives defined but in an error condition (as they would be on a laptop operating outside the network). Even when the unconnected network drive is not the next available drive letter, Windows XP may be unable to map a drive and this error may also prevent the mounting of the USB device.

Common assignments

Applying the scheme discussed above on a fairly modern Windows based system typically results in the following drive letter assignments:

    * A: — Floppy disk drives, 3.5" or 5.25", and possibly other types of disk drives, if present, and supported by the BIOS.
    * B: — Unused, reserved for a second floppy drive.
    * C: — First hard disk partition.
    * D: to Z: — Other disk partitions get labeled here. Windows 9x assigns the next free drive letter to the next drive it encounters while enumerating the disk drives on the system (during installation). Drives can be partitioned, thereby creating more drive letters. This applies to MS-DOS, as well as ALL Windows operating systems. Windows offers other ways to change the drive letters, either through the Disk Manager (Windows NT, 2000, XP and later) or through the Device Manager found in the Control Panel. MS-DOS typically uses parameters on the line loading device drivers inside the config.sys file. Because Windows 9x is based on MS-DOS, those drive letters as established inside the config.sys file also apply to Windows 9x systems.
    * D: to Z: — CD-ROM, DVD, or shared network drives begin after the last used hard drive partition drive letter.
    * F: — First network drive if using Novell NetWare
    * Z: — First network drive if using Banyan VINES, and the initial drive letter assignment for the virtual disk network in the DOSBox x86 emulator.

The C: drive usually contains all of the Windows operating system files required for operation of the computer. On many modern personal computers, only one hard drive with one partition is present, so it is designated C:. On such a computer, all of a user's personal files are often stored in directories on this drive as well. These drives can, however, be different.

When there was no second physical floppy drive, the B: drive was used as a "virtual" floppy drive mapped onto the physical A: drive, whereby the user would be prompted to switch floppies every time a read or write was required to whichever was the LEAST recently used of A: or B:. This allowed for much of the functionality of two floppy drives on a computer that had only one.

Network drives are often assigned letters towards the end of the alphabet. This is often done to differentiate them from local drives: by using letters towards the end, it reduces the risk of an assignment conflict. This is especially true when the assignment is done automatically across a network (usually by a logon script).

It is not possible to have more than 26 drives. If access to more filesystems than this is required, volume mount points must be used.