Proxy settings for update

[walkman]

I'm using proxy for internet connection, so I check box "Use proxy to ...", but I got message " Cannot open file "" ". I got this message on 3 of 4 computers: windows 2000, 2000 server (it's OK), XP, 2003 server. How I can resolve problem?

[walkman]

I'm using proxy for internet connection, so I check box "Use proxy to ...", but I got message " Cannot open file "" ". I got this message on 3 of 4 computers: windows 2000, 2000 server (it's OK), XP, 2003 server. How I can resolve problem?

Also I got "Socket error # 10060" clicking on "Search for updates" button.