You get the "can't find a certificate to validate the server" error message if you either don't have the matching root cert, or if it isn't enabled for WLAN connections. If you can figure out which CA your Radius server certificate is from (eg. Entrust? Verisign? ask the Radius admin guys), then go into Control panel / Certificate manager / Authorities tab and you'll probably see the root certificate that matches the Radius cert. Select it and choose Trust, then check the WLAN box. If you've got it right, you should no longer see that error message. Sorry, can't help you on the "Require client auth" checkbox in Advanced / EAP... I don't need/use it. technut Peter Flynn wrote: > > Problem solved. > > When you edit a WPA connection, and get to the end, and click on > Advanced, and click on the EAP tab to set the parameters, the "Require > client authentication" is ambiguous, as I mentioned. If you leave it > unchecked, then when you try to connect, you get the error message > saying that it "can't find a certificate to validate the server". > > I then clicked Cancel, as it was "obvious" that connection had failed. > > Wrong. The message is a comment only: if you click on OK it goes right > ahead and connects just fine.