NTinternals. PEB. Typedef struct _PEB { Structure PEB (Process Enviroment Block) contains all User-Mode parameters associated by system with current process.
RTL_USER_PROCESS_PARAMETERS. Typedef struct _RTL_USER_PROCESS_PARAMETERS { ULONG MaximumLength; ULONG Length; ULONG Flags; ULONG DebugFlags; PVOID ConsoleHandle; ULONG ConsoleFlags; HANDLE StdInputHandle; HANDLE StdOutputHandle; HANDLE StdErrorHandle; UNICODE_STRING CurrentDirectoryPath; HANDLE CurrentDirectoryHandle; UNICODE_STRING DllPath; UNICODE_STRING ImagePathName; UNICODE_STRING CommandLine; PVOID Environment; ULONG StartingPositionLeft; ULONG StartingPositionTop; ULONG Width; ULONG Height; ULONG CharWidth; ULONG CharHeight; ULONG ConsoleTextAttributes; ULONG WindowFlags; ULONG ShowWindowFlags; UNICODE_STRING WindowTitle; UNICODE_STRING DesktopName; UNICODE_STRING ShellInfo; UNICODE_STRING RuntimeData; RTL_DRIVE_LETTER_CURDIR DLCurrentDirectory[0x20];
DRIVE_LETTER_CURDIR.