Unable to change the Way of Logon & Logoff in XP

This might cause because of any one below

1. If service CLIENT FOR NETWARE NETWORKS is running along with ur TCP/IP in network connections .....in this case simply do uninstall this service from network connection properties..........

2. If any of files related to winlogon most propably files like MrvGINA.dll replaced by new drivers/softwares raises this issue leading to not change the way of winlogon and this even causes problem in initiation of remote desktop connections...........

to solve this problem simply

go to registry and search MrvGINa.dll under
HKEY_LOCAL_MACHINE/SOFTWARE/MICROSOFT/WINDOWSNT/CURRENTVERSION/
WINLOGON path , then delete
and do a restart . .But be sure to take backup of registry before deleting it helps you..if not search here
HKEY_CURRENT_USER/SOFTWARE/MICROSOFT/WINDOWSNT/WINLOGON
path, then delete it, reboot your PC and enjoy!