Remote Desktop is a feature that was introduced by Microsoft in Windows XP Professional. It is the latest version of Microsoft's Terminal Server software, and is available only on Windows XP Professional.
The Microsoft Terminal Server software debuted with Windows NT 4.0 Terminal Server Edition, and was designed to allow one server to have installed applications and allow many thin clients to connect remotely to the terminal and view, in a window, the entire Windows desktop, and to allow the user to control the remote computer as though the person were in front of the computer. Because of the multi-user design of Windows NT, it was possible to allow many people to log into the server simultaneously. Unfortunately, hardware was not yet at the level of the software, and Terminal Server was a less than phenomenal success.
Microsoft nonetheless persevered and continued to improve the terminal server software, and when Windows 2000 Server was released, it included a new version of the software. Rather than releasing a special edition of Windows 2000 Server, Microsoft instead opted to include the terminal server software with all versions of the Windows 2000 Server family. The software also had two options when being installed; one could opt to run the software in the traditional mode, allowing many users to connect at once, or one could opt to run the software in remote administration mode, which would allow a small number of users to connect remotely, provided they were administrators. The only difference between the two, functionally, was that non-administrators could remotely connect when using the traditional mode, and that licensing was required when using the traditional mode.
When Windows XP was being developed, Microsoft decided to include terminal services in it. Rather than giving the ability to allow unlimited users to connect to the terminal server for the low cost of $299, Microsoft crippled the software in Windows XP and forced it to allow only one user to connect at a time. Microsoft integrated multiple user connections in Windows XP Professional as it had done in NT 4 Terminal Server and Windows 2000 Server, and developed a technology dubbed "Fast User Switching" which allowed more than one person to be logged on at a time locally. Users could use the "Lock Workstation" feature to return to the login screen, and log in as a different user, with the other person's session still running hidden. Because of this, Remote Desktop has a few new features that weren't present before.
Remote Desktop functions by allowing remote connections to take precedence over local sessions, so that if a remote user connects to the machine, the local user is locked out of the machine while the second user logs in. In addition, there is an extension of Remote Desktop called Remote Assistance, which allows a user to take over the computer of the person using it. Rather than locking the person out of the computer, the screen freezes while the remote person connecting to the machine uses it, allowing the locally logged on person to see what the remote user is doing.
Further, Remote Desktop, if used with the latest version of Microsoft's Remote Desktop client (which is backwards compatible with Windows 2000 Server and Windows NT 4.0 Terminal Server), allows users to specify display settings and sound and printer settings. In the past, Terminal Server had three options when connecting to a remote machine: screen resolution, the caching of bitmaps for faster screen loading, and enabling compression for the connection. Remote Desktop on the other hand allows for the following:
- Specify username and password
- Specify domain
- Screen resolution
- Color depth
- What to do with sounds played remotely (do not play, do not download)
- Use window hotkeys and key combinations on remote machine instead of local machine
- Connect remote disk drivers, printers, and serial devices from remote machine
- Start programs on the remote machine automatically when connecting
- Display the remote desktop background (usually costs more bandwidth)
- Show window contents while dragging
- Use menu and window animation (slide only, not alpha-blending)
- Show themes (Visual Styles used in Windows XP)
- Cache bitmaps
If used with a low color depth (256 colors) and not using themes or window animation, Remote Desktop performs well over a 128kbps uplink, and functions extremely well over a LAN.
Aside from the differences in the client/server communications, Remote Desktop differs from the previous versions of Terminal Server in that it only allows one user to use the terminal services at a time, and cannot be changed to do otherwise. It is not available in Windows XP Home Edition, though Home Edition users can connect to a Professional Edition workstation.