Unix Crypt passwords + Windows 7

Have I exhausted all of my options? Is there anything I’m missing? I have an existing database of users with their passwords encrypted using Unix crypt(). A wireless AP is set for WPA/WPA2 using the RADIUS server to validate user logins. This works great using EAP-GTC for all clients except Windows. Windows doesn’t support EAP-GTC. Here are a few things I can’t do: • Install certificates on the Windows clients • Install a supplicant on the Windows clients Is there anything I can do to get the Windows clients to authenticate without changing the Windows configuration? Any help is greatly appreciated. Thanks, Thomas