Glossary
NTUSER.DAT
The main per-user registry hive (HKCU). It holds the Windows XP ShellBags and, on later versions, a second, smaller BagMRU tree.
NTUSER.DAT, at the root of each profile (C:\Users\<user>\NTUSER.DAT), is the hive behind HKEY_CURRENT_USER. On Windows XP it held all ShellBags (Software\Microsoft\Windows\ShellNoRoam and Shell). On Vista and later it keeps its own Software\Microsoft\Windows\Shell\BagMRU tree, usually smaller than the one in UsrClass.dat.
It also holds RecentDocs, ComDlg32 MRUs and the Shell Folders values that reveal the account name. Always parse it together with UsrClass.dat; see the complete guide.