I have a Windows 7 Professional 64 bit laptop joined to AD infrastructure. This one particular laptop won't allow me to login using User@domain.com. I can only login using DOMAIN\User. Any ideas why I can't login using the "e-mail format" user name?

make sure the particular computer name is registered in DNS. if not registered do please register forcefully by using this command ipconfig /registerdns once you are done. restart DNS service on the server side. try to login using the email name and let us know the result

Hi, Please refer to the suggestion provided by V.M. Also, you could check the audit logs in Event log and see what happened. Juke Chou TechNet Subscriber Support If you are TechNet Subscription user and have any feedback on our support quality, please send your feedbackhere.Juke Chou TechNet Community Support

Thanks for the suggestions. I checked DNS and followed your instructions but I believe the issue is isolated to specific computers not the server's DNS. I found the following in the Event Log - Application at the point I try to log on: Faulting application name: LogonUI.exe, version: 6.1.7601.17514, time stamp: 0x4ce79f70 Faulting module name: FpCredProv.dll, version: 3.3.0.50, time stamp: 0x4a9c9683 Exception code: 0xc0000409 Fault offset: 0x0000000000014894 Faulting process id: 0x3f0 Faulting application start time: 0x01cd2eb3f9fdce22 Faulting application path: C:\Windows\system32\LogonUI.exe Faulting module path: C:\Windows\system32\FpCredProv.dll Report Id: 498da9f2-9aa7-11e1-ac44-0022681ee630 Additionally, as an added clue, when typing on other machines the user@domain.com, as soon as you type in the @ symbol, the "Logon To:" begins to populate with the domain. It does not change on this machine. (Lenovo X301 laptop) After looking through the logs and comparing it to other Lenovo laptops, I believe this issue is related to the Fingerprint software. It may be interfering with the normal logon process. Thanks again for your help Juke and VM! Checked Lenovo's web site. There was a complete revision to the Password Manager program they provide. The new version (4.0) fixes the issue. Ican now log onto this laptop using user@domain.com.

Hi, Thanks for your update. I will mark your solution as Answered. If you have any further question, please let me know. Juke Chou TechNet Community Support