well i did setup everything from scratch according to the microsoft free eblook about lync 2013

and i joined a win 8.1 pc to my domain

when i try to login it ask me for password but when i enter it it says that 

cant sign in to lync

you didnt get signed in .it might be your sign-in address or logon credentials, so try those again. if that doesnt work,contact your support team

im desperate guys , plz help me

Hi Ali,

Is that your company has already having lync deployed environment? or you are using any O365 subscriptions? to login to lync client.

You required any one of the above mentioned lync environments to login to lync client.

could you please provide more Details of your lync environment/Deployment

If it is O365 Subscription

check this http://support.microsoft.com/kb/2541980

  

hi

im setuping lync server myself in a test environment

so there is no subscription

and i did setup everything accourding to the free ebook that microsoft provided

Hi AliReza Baensaf,

You can follow the steps below to troubleshoot the issue.

1. Please check whether or not all the Lync services are running.

2. Make sure the required DNS records are set up.

DNS requirements for Front End pool in Lync Server 2013

DNS requirements for automatic client sign-in in Lync Server 2013

3. Please try manual configuration to test the issue.

4. You can enable Lync client logging and use snooper to analyze it.

5. Install the updates for both Lync server and Lync client.

Best regards,

Eric

• Edited by Eric_YangKModerator Monday, January 26, 2015 2:52 AM

Hi AliReza Baensaf,

You can follow the steps below to troubleshoot the issue.

1. Please check whether or not all the Lync services are running.

2. Make sure the required DNS records are set up.

DNS requirements for Front End pool in Lync Server 2013

DNS requirements for automatic client sign-in in Lync Server 2013

3. Please try manual configuration to test the issue.

4. You can enable Lync client logging and use snooper to analyze it.

5. Install the updates for both Lync server and Lync client.

Best regards,

Eric

• Edited by Eric_YangKModerator Monday, January 26, 2015 2:52 AM

This could be a policy mis-match issue between the client PC and the front end server. Have a look at below thread explaining about this problem. Or could be certificate issue or time mis-match between the client and the server

http://blogs.technet.com/b/rogulati/archive/2011/04/30/lync-2010-ntlm-sec-policy-mismatch-error-cannot-sign-from-xp-clients.aspx