time/date problem with XP

Archived from groups: microsoft.public.windowsxp.perform_maintain (More info?)

my pc will not keep the current time and date. i have replaced the
motherboard battery and syncronized with the two available time/date sites to
no avail. this problem began after someone bypassed my desktop logon and
created his own. don't know if this part of the problem, but the timing is
noteworthy.

any help would be greatly appreciated.