Which file contains the User Assist data in Windows environments?

The file that contains the User Assist data in Windows environments is NTUSER.DAT. This file is part of the Windows Registry and is located within each user's profile directory. It stores user-specific configuration settings, including the User Assist data, which tracks the applications that the user has launched and their execution counts. This information is useful in forensic investigations as it helps to establish the actions and behaviors of users on a system.

In contrast, SYSTEM.DAT is typically associated with system-level registry data, USERINFO.DAT is not a standard or recognized Windows registry file, and APPDATA.DAT does not correspond to any specific Windows file relevant to user activity tracking. Therefore, NTUSER.DAT is crucial for understanding user activity due to its role in maintaining user-specific data, including the User Assist entries.