|A physical drive's partition must be software partitioned, using a type of organization Windows recognizes - NTFS, FAT32, or FAT - then the software created organization must be Formatted so that data can be stored on it. In Windows 2000 and up, those two things are done at nearly the same time when you make a new partition on a physical drive, the software partitioning starting a little ahead of the formatting. |
When you RIGHT click on a partition's drive letter in My Computer or Windows Explorer and choose Format, you are only Formatting it.
The physical hard drive always has at least one partition on it, if at least one drive letter shows up for it in My Computer and Windows Explorer.
Control Panel - Classic view - Administrative Tools - Computer Management - Disk Management.
The space on the physical hard drive(s) show(s) up there graphically - it(they) have an icon different from that for an optical (CD or DVD) drive .
The box to the right of the icon shows whether there are (software created) partitions on the physical drive.
If the hard drive has one or more partitions that Windows recognizes, the partition is labelled as xxxGB NTFS, (or FAT32, or FAT) Healthy , and usually there is a logical drive letter for that partition before xxxGB
If you have only one hard drive, only one partition that Windows recognizes on it, and Windows has been installed on it, then the label will say Healthy(System).
The partition that Windows was installed on that Windows was booted from is always labelled Healthy(System) - there can be only one of those on a computer at a time. It usually, but not always for XP or 2000, has the logical drive letter C .
You can have more than one (software created) partition on one physical hard drive - up to 4 Primary partitions (a dark blue bar above it ) , or up to three Primary partitions, and an Extended partition (a light blue bar above it ) , which can have one or more Logical partitions inside of it (within it).
If there is space on the physical drive that does not have a (software created) partition, that portion, or all, of the space on the physical drive, is labelled unallocated (a black bar above it ) , and has no drive letter .
A new hard drive, or a used hard drive that has no data at all on it, has no (software created) partitions.
If a partition is labelled Healthy (Unknown Partition) then Windows cannot show that partition in My Computer and Windows Explorer, and the computer user cannot place data on it in Windows.
Brand name computer original brand name software installations usually have two partitions on the original single physical hard drive - the second one is usually much smaller (sometimes the first one is much smaller), and it may show up here as Healthy (Unknown Partition), and if so it doesn't show up in My Computer or Windows Explorer. The remainder of the physical drive's space, the much larger partition, is where Windows and whatever other software the brand name provided was installed - that's seen as being assigned the C logical drive letter in My Computer and Windows Explorer.
If you have only one hard drive, only one software partition that Windows recognizes on it, then there are no other (software created) partitions that you could have installed your own data on.