ntrdps 0.6

Adds a login: a client must log on before it gets the console. It is on by default. Download the installer for your CPU. It finds the NT version itself. Log on as an administrator, run it, leave Require authentication ticked, choose Mirror Driver (NT 3.x: Layered Driver; fast, the default) or GDI Polling (slow, no driver), click Install, and let it restart Windows NT. On NT 3.1 and 3.5 it asks for the user name and password of the ntrdps account.

CPU	Installer	Tested on (QEMU)
Intel x86	ntrdpset-i386.exe	NT 3.1, 3.5, 3.51, 4.0 (also 4.0 SP1)
MIPS	ntrdpset-mips.exe	NT 3.1, 3.51, 4.0
Alpha	ntrdpset-alpha.exe	NT 3.1, 3.51, 4.0 (SP6a)
PowerPC	ntrdpset-ppc.exe	NT 3.51, 4.0

On MIPS with NT 3.1 or 3.51, and on PowerPC with NT 3.51, ntrdps reads the screen by polling, so updates are slower.

The MIPS, Alpha and PowerPC installers were added on 2026-11-11. On the same day all four installers got a shorter window (commit 274fa8b); the programs they install did not change.

New: the login

NT version	Who may log on
NT 3.51, 4.0	An account of the NT machine that is in the group Administrators. Windows checks the password.
NT 3.1, 3.5	The ntrdps account: one user name and password, set in the installer. These NT versions cannot check a Windows password for a program. ntrdps stores only a hash of the password.

• The client can send the user name and password itself (FreeRDP /u: /p:, rdesktop -u -p). When they are right, the client gets the console at once.
• If it sends none, or a wrong one, the client gets the logon dialog of Windows itself, on every NT version, in the machine's own language. The console never shows it. 3 wrong tries, or 60 s without a right login, end the connection.
• On NT 3.1 the From list of the dialog does not open: use the Up and Down keys.
• Plain RDP (no TLS) sends the password as plain text. To allow only TLS clients to log on: set the REG_DWORD LoginPlain = 0 in HKEY_LOCAL_MACHINE\SOFTWARE\ntrdps.
• Every copy of ntrdps has the same built-in TLS certificate, and its private key is public. So TLS stops someone who only listens. It does not stop someone who can get between you and the server: that one could read the password too. Use ntrdps only on a network you trust.
• An update turns the login on. On NT 3.1 and 3.5 the installer then asks for the ntrdps account. In a batch file there: ntrdpset /install /q /user:NAME /password:PASSWORD (or /nologin).
• No login, as in 0.5.1: untick Require authentication, or /nologin, or set the REG_DWORD Login = 0.

Fixed:

• NT 4.0 before Service Pack 3: a blue screen (STOP 0x1E, seen on SP1) while a client was connected, when a program sent a message to the desktop window. Since release 0.2. ntrdps now uses no hooks on these versions. With the display driver nothing else changes. Without it, the client shows its own arrow pointer.

Tested in QEMU, x86: NT 4.0 SP6a and NT 3.1 with rdesktop 1.9.0 (TLS) and FreeRDP 3.15.0 (TLS and plain), NT 4.0 also with mstsc 5.1; NT 3.51, NT 3.5 and NT 4.0 SP1 with FreeRDP (TLS). MIPS, Alpha and PowerPC: NT 3.1 (not PowerPC), NT 3.51 and NT 4.0 with FreeRDP (TLS). Current Microsoft clients (mstsc of Windows 10, Windows App) were used with ntrdps, but they are not in our tests yet.