Essentially, the answer is "No".
Windows XP is a "Workstation" OS which limits the system to only having a single user session active at any given time.
Depending on your system's configuration, it may be possible to have more than one person logged into the system at once. But, only one person can actually be using the system at a time.
If you were to log into the system (locally or remotely) while someone else was working on it, the other user would at minimum have their session suspended and be returned to the login screen - at worst, their session would be terminated entirely. Depending on the other user's privileges, they may not be able to resume their session or log in again until you are done with the system - if they are able, such action would then result in your session being suspended or terminated.