Probably not a good idea to try and perform an update through a proxy through a dial-up connection. Have you tried it without the proxy, or are you required to use the proxy?

Originally Posted by Kbayin

I´ve got a dial up conection thru a proxy and i can´t update the windows defender when I try show this error message:
0x8024402c Windows defender couldn´t install the definition updates because the proxy server or taget server name can´t be resolve.
Any help about this?

What is the proxy for, it could be trying to access the proxy server which might not allow you to obtain the updates.

Have you tried not going via proxy?