I not sure to understand your question correctly. You want to authenticate your P6 V7 environment using the windows users and passwords from tha Active Directory. Is that correct?
If yes, then you can use the LDAP authentication to use your AD users. Therefore you can change the settings for the WebAccess and P6 Client using the ldap-config tool. That you can find in the Project Management Client install package under /database/ldap-config. That is working fine. Keep in mind that you can only use one authentication method per WebAccess (all PMDB and MMDB have to use the same authentication).
If you truely ment SSO-Technology I have to admit I haven't seen that with the P6 Client V7.