I was trying to enable users in Microsoft Lync server.I was unable to find some active directory users in Microsoft Lync server.My configuration was proper.I was able to find users but not all users.
At the end i find there was office communicator server was installed before and i twas removed. but the users for office communicator was still enabled in active directory and pointing to the old office communicator server. I find solution on http://ingazat.wordpress.com/
After removing OCS user information form AD I was able to find users in Lync Server.

1- On Active Directory open ADSIEdit
2- Point to where your users reside
3- Right click on your user and select properties and clear the following attributes :
msRTCSIP-PrimaryHomeServer
msRTCSIP-PrimaryUserAddress
msRTCSIP-User Enabled to “Not Set”