Lync Basic Client and OCS server 2007 R2 error Cannot synchronize with the corporate address book

Hi,

We are running OCS server 2007 R2 standard E and OCS client and so for this setup is running fine.

I have installed Lync Basic Client on windows 7 computer and its connecting to our OCS server 2007 R2, but I am unable search any users from the lync basic client it says "No Match found" and getting error "Cannot synchronize with the corporate address book. This may be because the proxy server setting in your web browser does not allow access to the address book"

Wherein OCS client is working fine.

I didn't changed any setting on OCS Server 2007 R2.

please advise how do I fix this issue.