Win7 Ldap Auth without RootCA

Hello, I'm trying to run ldap auth with FreeRADIUS Version 2.1.10 (Debian Squeeze) and FreeRADIUS Version 2.1.12 (FreeBSD 9.0) with a self-signed certificate. It is working for all platform excepted Win7 supplicant. I found few stuff talking about this problem but i want to be sure. Any way to do this working without change security settings on all roaming clients? Regards, Matt