What Is a Registry Hive?

A hive in the Windows Registry is the name given to a major section of the registry that contains registry keys, registry subkeys, and registry values.

All keys that are considered hives begin with "HKEY" and are at the root, or the top of the hierarchy in the registry, which is why they're also sometimes called root keys or core system hives.

To use a more common term, a hive is like a starting folder in the registry. Everything in the registry is ultimately contained in various hives.

Where Are the Registry Hives Located?

In Registry Editor, the hives are the set of registry keys that appear as folders on the left-hand side of the screen when all other keys have been minimized.

Here is a list of the common registry hives in Windows:

• HKEY_CLASSES_ROOT
• HKEY_CURRENT_USER
• HKEY_LOCAL_MACHINE
• HKEY_USERS
• HKEY_CURRENT_CONFIG

HKEY_DYN_DATA is a registry hive that was used in Windows ME, 98, and 95. Most of the information stored in that hive is stored in HKEY_LOCAL_MACHINE\HARDWARE in later versions of Windows.

Why Can't I See Any Registry Hives?

Sometimes, when you open Registry Editor, you'll see lots and lots of folders on the left side, and maybe even registry values on the right side, but not any registry hives. This just means they're out of the normal viewing area.

To see all the registry hives at once, scroll to the very top of the left side of the Registry Editor and collapse all the hives, either by selecting the down arrows or choosing Collapse from the right-click menu.

Either way, this will minimize all the keys and subkeys so you just see the handful of registry hives listed above.

Registry Hive vs Registry Key

A registry hive is a folder in the Windows Registry, but so is a registry key. So what exactly is the difference between a registry hive and registry key?

The only difference between the two is that a registry hive is the first folder in the registry, and it contains registry keys, whereas the registry keys are the folders inside the hives that contain registry values and other registry keys.

Naming a folder in the registry a "registry hive" is only done to further categorize what it is that we're talking about. Instead of calling every folder in the registry a registry hive or a registry key, we call the major, first folder a hive but use key as the name of every other folder inside the hives, and registry subkeys as the term for keys that exist within other keys.

A Registry Hive in Context

Here is an easy way to understand where a registry hive belongs in the Windows Registry:

HIVE\KEY\SUBKEY\SUBKEY\...\...\VALUE

As you can see in the example below, while there may be multiple registry subkeys below a hive, there's always only just one registry hive within each location.

HKEY_CURRENT_USER\Control Panel\Desktop\Colors\Menu

• HIVE: HKEY_CURRENT_USER
• KEY: Control Panel
• SUBKEY: Desktop
• SUBKEY: Colors
• VALUE: Menu

Editing and Deleting Registry Hives

Registry hives, unlike keys and values, can't be created, deleted, or renamed. Registry Editor won't let you, meaning you can't even accidentally edit one.

Being unable to remove registry hives isn't Microsoft keeping you from doing something amazing with your own computer—there's simply no reason you'd ever want to. The keys and values that comprise all the registry hives are where the real value of the Windows Registry is.

You can, however, add, change, and delete keys and values in the registry. You need to access the hives to do any of that, but the hives themselves are unchangeable.

Backing Up Registry Hives

You can, however, back up registry hives, just like you can registry keys. Backing up an entire hive saves all the keys and values within that hive as a REG file that can then be imported back into the Windows Registry at a later time.

See How to Back Up the Windows Registry, and the accompanying How to Restore the Windows Registry, for more.