Every version of Microsoft Windows from Windows XP onward[5] includes an installed Remote Desktop Connection [RDC] ["Terminal Services"] client [mstsc.exe] whose version is determined by that of the operating system or by the last applied Windows Service Pack. The Terminal Services server is supported as an official feature on Windows NT 4.0 Terminal Server Edition, released in 1998, Windows 2000 Server, all editions of Windows XP except Windows XP Home Edition, Windows Server 2003, Windows Home Server, on Windows Fundamentals for Legacy PCs, in Windows Vista Ultimate, Enterprise and Business editions, Windows Server 2008 and Windows Server 2008 R2 and on Windows 7 Professional and above.
Microsoft provides the client required for connecting to newer RDP versions for downlevel operating systems. Since the server improvements are not available downlevel, the features introduced with each newer RDP version only work on downlevel operating systems when connecting to a higher version RDP server from these older operating systems, and not when using the RDP server in the older operating system.[clarification needed]
Version 4.0Edit
Based on the ITU-T T.128 application sharing protocol [during draft also known as "T.share"] from the T.120 recommendation series, the first version of RDP [named version 4.0] was introduced by Microsoft with "Terminal Services", as a part of their product Windows NT 4.0 Server, Terminal Server Edition.[1] The Terminal Services Edition of NT 4.0 relied on Citrix's MultiWin technology, previously provided as a part of Citrix WinFrame atop Windows NT 3.51, in order to support multiple users and login sessions simultaneously. Microsoft required Citrix to license their MultiWin technology to Microsoft in order to be allowed to continue offering their own terminal-services product, then named Citrix MetaFrame, atop Windows NT 4.0. The Citrix-provided DLLs included in Windows NT 4.0 Terminal Services Edition still carry a Citrix copyright rather than a Microsoft copyright. Later versions of Windows integrated the necessary support directly. The T.128 application sharing technology was acquired by Microsoft from UK software developer Data Connection Limited.[6]
Version 5.0Edit
This version was introduced with Windows 2000 Server, added support for a number of features, including printing to local printers, and aimed to improve network bandwidth usage.
Version 5.1Edit
This version was introduced with Windows XP Professional and included support for 24-bit color and sound. The client is available for Windows 2000, Windows 9x, Windows NT 4.0.[7] With this version, the name of the client was changed from Terminal Services Client to Remote Desktop Connection; the heritage remains to this day, however, as the underlying executable is still named mstsc.exe.
Version 5.2Edit
This version was introduced with Windows Server 2003, included support for console mode connections, a session directory, and local resource mapping. It also introduces Transport Layer Security [TLS] 1.0 for server authentication, and to encrypt terminal server communications.[8] This version is built into Windows XP Professional x64 Edition and Windows Server 2003 x64 & x86 Editions.
Version 6.0Edit
This version was introduced with Windows Vista and incorporated support for Windows Presentation Foundation applications, Network Level Authentication, multi-monitor spanning and large desktop support, and TLS 1.0 connections.[9] Version 6.0 client is available for Windows XP SP2, Windows Server 2003 SP1/SP2 [x86 and x64 editions] and Windows XP Professional x64 Edition. Microsoft Remote Desktop Connection Client for Macintosh OS X is also available with support for Intel and PowerPC Mac OS versions 10.4.9 and greater.
Version 6.1Edit
This version was released in February 2008 and is included with Windows Server 2008, as well as with Windows Vista Service Pack 1. The client is included with Windows XP SP3.[10] In addition to changes related to how a remote administrator connects to the "console",[11] this version has new functionality introduced in Windows Server 2008, such as connecting remotely to individual programs and a new client-side printer redirection system that makes the client's print capabilities available to applications running on the server, without having to install print drivers on the server[12][13] also on the other hand, remote administrator can freely install, add/remove any software or setting at the client's end. However, to start a remote administration session, one must be a member of the Administrators group on the server to which one is trying to get connected.[14]
Version 7.0Edit
This version was released to manufacturing in July 2009 and is included with Windows Server 2008 R2, as well as with Windows 7.[15] With this release, also changed from Terminal Services to Remote Desktop Services. This version has new functions such as Windows Media Player redirection, bidirectional audio, multi-monitor support, Aero glass support, enhanced bitmap acceleration, Easy Print redirection,[16] Language Bar docking. The RDP 7.0 client is available on Windows XP SP3 and Windows Vista SP1/SP2 through KB969084.[17] The RDP 7.0 client is not officially supported on Windows Server 2003 x86 and Windows Server 2003 / Windows XP Professional x64 editions.
Most RDP 7.0 features like Aero glass remote use, bidirectional audio, Windows Media Player redirection, multiple monitor support and Remote Desktop Easy Print are only available in Windows 7 Enterprise or Ultimate editions.[18][19]
Version 7.1Edit
Release 7.1 of RDP was included with Windows 7 Service Pack 1 and Windows Server 2008 R2 SP1 in 2010. It introduced RemoteFX, which provides virtualized GPU support and host-side encoding.
Version 8.0Edit
This version was released in Windows 8 and Windows Server 2012. This version has new functions such as Adaptive Graphics [progressive rendering and related techniques], automatic selection of TCP or UDP as transport protocol, multi touch support, DirectX 11 support for vGPU, USB redirection supported independently of vGPU support, etc.[20][21] A "connection quality" button is displayed in the RDP client connection bar for RDP 8.0 connections; clicking on it provides further information about connection, including whether UDP is in use or not.[22]
The RDP 8.0 client and server components are also available as an add-on for Windows 7 SP1. The RDP 8.0 client is also available for Windows Server 2008 R2 SP1, but the server components are not. The add-on requires the DTLS protocol to be installed as prerequisite.[22] After installing the updates, for the RDP 8.0 protocol to be enabled between Windows 7 machines, an extra configuration step is needed using the Group Policy editor.[23]
A new feature in RDP 8.0 is limited support for RDP session nesting; it only works for Windows 8 and Server 2012 though, Windows 7 and Server 2008 R2 [even with the RDP 8.0 update] do not support this feature.[24]
The "shadow" feature from RDP 7, which allowed an administrator to monitor [snoop] on a RDP connection has been removed in RDP 8. The Aero Glass remoting feature [applicable to Windows 7 machines connecting to each other] has also been removed in RDP 8.[21][22]
Version 8.1Edit
This version was released with Windows 8.1 and Windows Server 2012 R2. A RDP 8.1 client update exists for Windows 7 SP1 as well, but unlike the RDP 8.0 update for Windows 7, it does not add a RDP 8.1 server component to Windows 7. Furthermore, if RDP 8.0 server function is desired on Windows 7, the KB 2592687 [RDP 8.0 client and server components] update must be installed before installing the RDP 8.1 update.[25][26]
Support for session shadowing was added back in RDP version 8.1. This version also fixes some visual glitches with Microsoft Office 2013 when running as a RemoteApp.[25]
Version 8.1 of the RDP also enables a "restricted admin" mode. Logging into this mode only requires knowledge of the hashed password, rather than of its plaintext, therefore making a pass the hash attack possible.[27] Microsoft has released an 82-page document explaining how to mitigate this type of attack.[28]
Version 10.0Edit
Version 10.0 of the RDP includes the following new features: AutoSize zoom [useful for HiDPI clients]. In addition graphics compression improvements were included utilizing H.264/AVC.[29]