Welcome to the first part of our Windows Forensics series!

Today we start a guide designed especially for beginners getting started with registry analysis. In digital forensics, few artifacts are as rich, subtle, and revealing as the Windows Registry. It is a sprawling, hierarchical database where Windows quietly stores its configuration details, such as system settings, user preferences, hardware and software information. But more than that, the Registry is a historical logbook, it records traces of what has happened on a machine, which applications were installed, devices were plugged in, and network connections occurred. Even after files are deleted, or an attacker attempts to erase evidence, residual entries often remain in registry hives, transaction logs, or backups. They can provide a trail that can be reconstructed. By learning how to read, interpret, and extract data from these structures, you gain access to a powerful source of truth about past system activity.

To illustrate just how powerful registry forensics can be, here is a real case described by Italian investigators. An employee was accused of leaking sensitive company data using a corporate workstation. When forensic investigators seized the machine and analyzed its system registry, they didn’t just stop at installed software or user activity. They homed in on power and standby settings to determine how the computer behaved when it was left idle and whether it asked for a password on reactivation. Through registry analysis, they discovered that the screen reactivated without requiring a login, which supported their theory that someone else might have used the computer under the guise of the employee.

Today we will start by unpacking the basic building blocks, such as the hives, the logs, and how to acquire them safely without altering critical metadata. With that foundation, you will be ready to move forward into more advanced analysis in later parts of the series.

Hives

When you first step into the world of the Windows Registry, it helps to imagine it as a branching structure that starts broad and becomes more detailed the deeper you go. At the top of this structure are the hives, which act as major containers for everything stored in the Registry. Inside these hives are keys, which behave like folders, and values, which contain the actual pieces of data.

The most important hives for forensic work are:

1. HKEY_LOCAL_MACHINE (HKLM), which contains system-wide settings 
2. HKEY_USERS (HU), which holds profile information for every user on the system 
3. HKEY_CURRENT_USER (HKCU), which shows the active user’s settings and is really just a shortcut to that user’s section inside HKEY_USERS
4. You may also encounter HKEY_CLASSES_ROOT and HKEY_CURRENT_CONFIG, but these are built from other hives and are usually less important when you are first learning registry forensics.

How you access these hives depends on whether you are analyzing a live machine or working with a disk image. On a live system, regedit.exe loads and mounts everything for you automatically, making navigation straightforward. On an image, nothing is mounted, so you must know where the actual hive files are located. Most system hives are stored in C:\Windows\System32\Config as DEFAULT, SAM, SECURITY, SOFTWARE, and SYSTEM, each corresponding to a specific Registry root.

User-specific hives are stored separately. On Windows 7 and newer, each user’s profile folder at C:\Users\<username>\ contains two important files: NTUSER.DAT and USRCLASS.DAT. When a user logs in, NTUSER.DAT becomes HKEY_CURRENT_USER and reflects personal settings, activity traces, and behavior, while USRCLASS.DAT loads under HKEY_CURRENT_USER\Software\CLASSES. Together, these hives give investigators an extremely detailed view of both system-level and user-level activity.

Another hive worth learning early on is the Amcache hive, located at C:\Windows\AppCompat\Programs\Amcache.hve. Windows uses it to record details about programs that were recently executed. Even if an attacker deletes an executable or removes its traces from other locations, Amcache often preserves enough information to connect it back to the system.

Now let’s take a closer look at the main hives and what makes each of them valuable in an investigation.

SAM Hive

The SAM hive stores local user accounts, groups, and password hashes. Investigators use it to identify accounts, check for unauthorized creations, and extract password hashes for deeper analysis. It often reveals privilege escalation attempts.

SYSTEM Hive

The SYSTEM hive contains configuration data for hardware, services, drivers, and network interfaces. It plays a major role in building system timelines because it stores time zone settings, device history, and information about previous network connections.

SOFTWARE Hive

The SOFTWARE hive contains records about installed software, both from Windows and third-party vendors. It can reveal when a program was installed, how it was configured, or whether malware established persistence on the system.

SECURITY Hive

The SECURITY hive contains local security policies and audit settings. Investigators look here to see whether someone changed security rules, weakened protections, or modified privilege rights.

NTUSER.DAT Hive

NTUSER.DAT gives the most detailed view of a specific user’s actions. It logs things like recently opened files, commands, application usage, and settings that reflect day-to-day behavior. It is one of the most valuable hives in user-focused investigations.

USRCLASS.DAT

USRCLASS.DAT holds additional user-level data related to the Windows interface, including recent items, folder views, and file associations. These small details often help reconstruct how a user navigated the system.

Amcache Hive

The Amcache hive records program execution history, even for deleted or moved executables. Because of this, it is extremely useful during malware investigations and incident response.

Transaction Logs and Backups

Beyond the hives, transaction logs and backups offer additional layers of evidence. Transaction logs act as journals that record Registry changes before they are written into the main hive files. If a system crashes or an attacker interrupts a process, the logs may still contain the most recent modifications. Each hive has a .LOG file stored in the same directory, and some hives have .LOG1 and .LOG2 as well. These files often reveal changes that are invisible in the main hives.

Registry backups work in the opposite direction by preserving older versions of the hives. Windows automatically copies the hives into C:\Windows\System32\Config\RegBack every ten days. When you suspect that keys were deleted or modified to cover tracks, comparing the current hives with their backups can reveal exactly what changed.

Before you can analyze any of this information, you must acquire the Registry hives safely. Registry acquisition is about collecting the hive files without altering them and preserving their metadata. Whether you are working on a live system or a disk image, your goal is always the same. You need to extract the files in a forensically sound manner so you can examine them later. Three common tools used for this are Autopsy, KAPE, and FTK Imager.

Autopsy

Autopsy is an open-source forensic tool that lets investigators examine disk images easily. When handling Registry hives, Autopsy makes it simple to navigate to the correct directories and export the hive files without touching the original evidence. It is widely used in training and lab environments because of its clear interface and reliability.

Kape

KAPE (Kroll Artifact Parser and Extractor) is designed for quick collection of important forensic artifacts. Instead of manually browsing through directories, KAPE uses modules that automatically identify and extract the correct Registry hives. This makes it ideal for triage situations or tight time windows.

FTK Imager

FTK Imager is a well-known imaging and preview tool used to extract files from both live systems and images. You can browse the file system, locate hives such as SAM, SYSTEM, SOFTWARE, NTUSER.DAT, or Amcache, and export them with all metadata preserved. FTK Imager is popular because it allows clean, safe copying without altering the evidence.

Summary

The Windows Registry acts like a digital diary of a computer’s life, recording system settings and the actions of users over time. It stores details about installed applications, devices that connected to the machine, and which programs were run. Even when attackers or users try to cover their tracks, the Registry often retains enough evidence. Logs and backup copies can reveal changes that would otherwise be hidden. And because all of this data is stored in structured “hives,” each part of the Registry tells a different story, from user behavior to security settings to executed programs. To preserve this evidence, investigators must collect Registry data carefully, using tools that maintain the integrity and metadata of the files. When done right, examining the Registry gives a clear, reliable view into past activity.