User account always has trouble logging in. She has tried mutiple computers

i have 2008r2 domain win7 clients. have 1 client has been having trouble months.  has tried 4 different computers , when computer boots let sit 30 seconds , still gets "username or password incorrect"  gets error time , our helpdesk has tried forcing different passwords have set, etc.  if disconnects network connection, logs in fine every time , reconnects network , works.  cached credentails work, , other weird thing when gets username of passwd incorrect, query domain controllers , not show bad attempts , last bad passwd times remain unchanged.  have looked through every setting in account tab , have no ideas.  thinking time might incorrect in bios , fixed when windows time service, checked of , looks correct.  if reboots , continues retry lets in.  ideas?  have gone through of logs when has failed attempt , not seeing in there windows time service not finding source, etc or can explain why failing.  security log , system log 100% clean on computer nothing in either, when gets failures.  app log has stuff, not think it points anything.  dcs show audit failure of 5768-a kerberos authentication ticket(tgt) requested result 0x6

0x6

client not found in kerberos database

bad user name, or new computer/user account has not replicated dc yet

dave

hi

 as says that,there no event log on dc failure attempt,but need check user name failure attempt,there ip on failure attempt,this source of failure attempt.

also check if user account set on application&program,or mobile device try logon,etc..

Windows Server  >  Directory Services