Currently there exist some solutions that allow the connection of several remote sessions simultaneously on a Windows XP by using the native and proprietary Microsoft Remote Desktop Protocol (RDP). However, there are no free solutions, and these are essential in the Windows XP operating system because it does not provide (by default) terminal services for multiple users. Main of these applications are:
WinConnect by ThinSoft (Holdings) Inc.
XP Unlimited by IPConsult B.V.
XP/VS Server by Thinstuff s.r.o.
On the other hand, there is a patch that allows to increase the number of clients that can stay simultaneously connected to a Windows XP Professional through terminal services, i.e. using the native RDP provided by Microsoft in (some of) their Windows systems.
The only version of Windows XP that allows remote desktop access (by using the native RDP protocol) is the professional one. The home version of Windows XP does not support remote desktop access, and therefore it can not be patched.
The system must be updated with the Windows XP Service Pack 2 (SP2) or Service Pack 3 (SP3).
Fast User Switching must be turned on. To check this feature you can follow the Microsoft instructions: Start, Control Panel, User Accounts, Change the way users log on or off, and verify that the check box Use Fast User Switching is turned on.
The Windows system cannot be configured within a domain, therefore the system must be only configured as a member of a workgroup. To check it go to: Start, Control Panel, System, select the Computer Name tabulation and click in Change. Then make sure that your computer is configured as a member of a workgroup.
Terminal Server Patch for Windows XP Professional with Service Pack 2. Self installation. Limited to three simultaneous sessions. Provided by sala source.
Improved Terminal Server Patch for Windows XP Professional with Service Pack 2 without (known) limits on the number of simultaneous desktops (sessions). It includes a file with installation instructions.