Excude it from the domain in your computer settings and after that encryption will disappear.
If your windows XP Professional based PC is connected to a domain, you can not add a user to the domain. This must be done on the server, and added in the active directory. If you just want to add a user ( not on a domain ), then go to START - SETTINGS - CONTROL PANEL - USER ACCOUNTS
All that I have found so far involves making the PC leave the domain by joining a workgroup, then rejoining the domain.
domain
Classic
HelpServicesGroup
I think it can be connected in a peer to peer setup. Connect through a hub/switch or any networking. and proceed normally.it should work.anyway XP home can't be connected to a domain.
Interactive
user account and a computer account
The local computer name.
If your computer is part of a domain, you won't see the "Switch User" choice on logout. This is because that functionality is disabled for Domain-homed Windows machines.
Windows XP was published around October 25, 2001, and copyright protection lasts 95 years, so it will become public domain in the year 2096.