The minimum requirements for properly and securely deploying protected wireless connections are actually quite simple:
Windows Vista, Windows XP, Windows Server 2003, or Windows Server 2008 for the wireless client operating system. All of these have built-in support for IEEE 802.11 wireless access and IEEE 802.1x authentication.
At least two Remote Authentication Dial-In User Service (RADIUS) servers for authentication. The Network Policy Server role service of the Network Policy and Access Service role is a good choice for a RADIUS server to provide full functionality.
Active Directory Domain Services for user account authentication and authorization.
Placing the NPS server on a domain controller will optimize authentication ...