Afraid I've got the same basic problem as everyone else. Can't be sure when, but it seems about the time I updated the main program to 4.5 a few days back that the error message "cannot connect to server" first started appearing. I've always been able since then to manually update.
Before registering with this forum, I did an uninstall and a reinstall, updated (manually) to 4.5 and updated the latest definitions 0451 (rebooting as appropriate).
I have McAfee firewall and had no problems before. Among other progs, McAfee is letting ashserv.exe and ashmaisv.exe access the internet. I've disabled the firewall and still no joy. I've tried autodetect and no proxy, all to no avail. I've tried the repair facility but it tells me it cannot connect to the server at the Downloads window.
I don't particularly wish to remove the firewall, reboot and then try again, which seems to me the last resort, since all else I've tried - and have seen posted here hasn't helped.
There appears to be a genuine problem, with the finger of suspicion pointing at Firewalls in general; so how's about Alwil software investigating a little further before we lay ourselves open by removing (albeit temporarily) our firewalls.
System is Athlon XP running windows XP home.
Regards
Dave