Changed DNS back to DHCP
No change.

At the moment there's a world wide attack happening on various DSL modems on TCP port 7547 which can cause anomalies, and is done to try to get malware on affected systems.

No one's asked yet, but what other things are you doing with those computers? Do any of them, or all of them, also have a torrent program on them and if so, are these active and if yes how many open ports do they have for downloads and uploads? As an example, when my wife downloads via her torrent client it can happen that I have neigh on no bandwidth left on my system all due to 200+ ports being open on her system slurping up all that bandwidth.

---

Nothing Torrent on it to my knowledge.
I loaded and configured this from scratch, and no one else has/had access.
I have not done much with it except to configure the OS, a few necessary programs, and run BOINC.
This build is to replace the older laptop; #1.
#1 is my day to day; email, web, etc.
#2 is going to replace a older desktop that is currently not up
No projects running except BOINC.
Just out of curiosity, I checked my account to see when #3 last contacted the server.
It was 30 Nov 2016, 21:35:09 UTC.
Thanks.

Just for reference, I was employed as a computer/network technician for 15 years prior to my retirement in September.

Ah - I'm self-taught, working as a consultant to small not-for-profit organisations - also retired now. But as a one-man-hand, I was my own final line of defence, and had to solve all the problems I threw at myself. I started just as networks were becoming relevant in small offices, so my first networking experience was the sort that requires a stepladder, an electric drill, and an 18" masonry bit...

I've found the emails relating to the reset commands. It was given to me by Symantec technical support in 2006, in the format "netsh winsock reset catalog" (reading MSDN, I now think the word 'catalog' was redundant). But it worked then, well enough for me to re-install my client's copy of NAV 2006, which was the objective of the call-out.

Is #3 a new machine, supplied with Windows 10, or an upgrade? Either way, I'd suggest a visual check of the hosts file - I've seen some malware put bad entries in there (though none specific to SETI), and some AV products put in blocking redirects to localhost. Windows 10 has the same file in the same place as always - C:\Windows\System32\drivers\etc\hosts - and an easier way of making hidden folders visible.

The only other thing I can think of at the moment is to run ping and tracert tests on boinc2.ssl.berkeley.edu - but it all seems OK if you can establish the initial connection before the 'Empty reply from server' at the next step. I'll keep scratching my head, but there's nothing else there at the moment.

One possibility is that that computer doesn't like HTTP 1.1 anymore and wants to be configured to have BOINC communicate via HTTP 1.0 with the project.

To do so, exit BOINC fully, navigate to the data directory C:\ProgramData\BOINC (which is hidden, so just fill in the path in Windows Explorer and hit Enter).
Getting there check if you already have a file called cc_config.xml and if not, make one. You can use Notepad or Notepad++ for this, no need for a fancy XML editor.

In it add the following:

<cc_config>
<log_flags>
</log_flags>
<options>
<http_1_0>1</http_1_0>
</options>
</cc_config>

Save the file as cc_config.xml, save as type 'all files', using ANSI encoding.

Afterwards restart BOINC and try with it to contact Seti.
I have asked the Seti devs to check that the server is configured correctly, as reading the cURL forums it may be that there's something wrong with it when it returns 'empty replies' or does not reply at all.

---

Hold that... Apparently there was a problem with download server 2 that Eric fixed. You can try again without changing HTTP first!

---

Thanks Jord.
File exists.
Does it matter where I place that configuration among the existing config?

<cc_config>
<log_flags>
<file_xfer>1</file_xfer>
<sched_ops>1</sched_ops>
<task>1</task>
<android_debug>0</android_debug>
<app_msg_receive>0</app_msg_receive>
<app_msg_send>0</app_msg_send>
<async_file_debug>0</async_file_debug>
<benchmark_debug>0</benchmark_debug>
<checkpoint_debug>0</checkpoint_debug>
<coproc_debug>0</coproc_debug>
<cpu_sched>0</cpu_sched>
<cpu_sched_debug>0</cpu_sched_debug>
<cpu_sched_status>0</cpu_sched_status>
<dcf_debug>0</dcf_debug>
<disk_usage_debug>0</disk_usage_debug>
<file_xfer_debug>0</file_xfer_debug>
<gui_rpc_debug>0</gui_rpc_debug>
<heartbeat_debug>0</heartbeat_debug>
<http_debug>1</http_debug>
<http_xfer_debug>0</http_xfer_debug>
<mem_usage_debug>0</mem_usage_debug>
<network_status_debug>0</network_status_debug>
<notice_debug>0</notice_debug>
<poll_debug>0</poll_debug>
<priority_debug>0</priority_debug>
<proxy_debug>0</proxy_debug>
<rr_simulation>0</rr_simulation>
<rrsim_detail>0</rrsim_detail>
<sched_op_debug>0</sched_op_debug>
<scrsave_debug>0</scrsave_debug>
<slot_debug>0</slot_debug>
<state_debug>0</state_debug>
<statefile_debug>0</statefile_debug>
<suspend_debug>0</suspend_debug>
<task_debug>0</task_debug>
<time_debug>0</time_debug>
<trickle_debug>0</trickle_debug>
<unparsed_xml>0</unparsed_xml>
<work_fetch_debug>1</work_fetch_debug>
</log_flags>
<options>
<abort_jobs_on_exit>0</abort_jobs_on_exit>
<allow_multiple_clients>0</allow_multiple_clients>
<allow_remote_gui_rpc>0</allow_remote_gui_rpc>
<client_version_check_url>http://boinc.berkeley.edu/download.php?xml=1</client_version_check_url>
<client_new_version_text></client_new_version_text>
<client_download_url>http://boinc.berkeley.edu/download.php</client_download_url>
<disallow_attach>0</disallow_attach>
<dont_check_file_sizes>0</dont_check_file_sizes>
<dont_contact_ref_site>0</dont_contact_ref_site>
<lower_client_priority>0</lower_client_priority>
<dont_suspend_nci>0</dont_suspend_nci>
<dont_use_vbox>0</dont_use_vbox>
<exit_after_finish>0</exit_after_finish>
<exit_before_start>0</exit_before_start>
<exit_when_idle>0</exit_when_idle>
<fetch_minimal_work>0</fetch_minimal_work>
<fetch_on_update>0</fetch_on_update>
<force_auth>default</force_auth>
<http_1_0>0</http_1_0>
<http_transfer_timeout>300</http_transfer_timeout>
<http_transfer_timeout_bps>10</http_transfer_timeout_bps>
<max_event_log_lines>2000</max_event_log_lines>
<max_file_xfers>8</max_file_xfers>
<max_file_xfers_per_project>2</max_file_xfers_per_project>
<max_stderr_file_size>0</max_stderr_file_size>
<max_stdout_file_size>0</max_stdout_file_size>
<max_tasks_reported>0</max_tasks_reported>
<ncpus>-1</ncpus>
<network_test_url>http://www.google.com/</network_test_url>
<no_alt_platform>0</no_alt_platform>
<no_gpus>0</no_gpus>
<no_info_fetch>0</no_info_fetch>
<no_priority_change>0</no_priority_change>
<os_random_only>0</os_random_only>
<process_priority>-1</process_priority>
<process_priority_special>-1</process_priority_special>
<proxy_info>
<socks_server_name></socks_server_name>
<socks_server_port>80</socks_server_port>
<http_server_name></http_server_name>
<http_server_port>80</http_server_port>
<socks5_user_name></socks5_user_name>
<socks5_user_passwd></socks5_user_passwd>
<http_user_name></http_user_name>
<http_user_passwd></http_user_passwd>
<no_proxy></no_proxy>
</proxy_info>
<rec_half_life_days>10.000000</rec_half_life_days>
<report_results_immediately>0</report_results_immediately>
<run_apps_manually>0</run_apps_manually>
<save_stats_days>30</save_stats_days>
<skip_cpu_benchmarks>0</skip_cpu_benchmarks>
<simple_gui_only>0</simple_gui_only>
<start_delay>0.000000</start_delay>
<stderr_head>0</stderr_head>
<suppress_net_info>0</suppress_net_info>
<unsigned_apps_ok>0</unsigned_apps_ok>
<use_all_gpus>0</use_all_gpus>
<use_certs>0</use_certs>
<use_certs_only>0</use_certs_only>
<vbox_window>0</vbox_window>
</options>
</cc_config>

Jord
did not change file
attempt still fails

Thanks Jord.
File exists.
Does it matter where I place that configuration among the existing config?

<cc_config>
    <options>
    ...
        <force_auth>default</force_auth>
        <http_1_0>0</http_1_0>
        <http_transfer_timeout>300</http_transfer_timeout>
    ...
    </options>
</cc_config>

You'll find it's there already, in alphabetical order in the lower half. Just change the 0 to a 1 between the tags.

(don't add a duplicate new row - the results can be undefined)

Well that did it!!!!
Once I saw the original config, I figured the value just had to be changed.
However, I waited for a reply before doing so.
Once done and BOINC restarted, the 4 startup files downloaded and I now have 13 tasks.
I had set the limit low while troubleshooting, but have raised it now.
Tasks are now rolling in.
Too weird. Both #1 and #2 values are set for 0.
I wonder why it suddenly would not work with 0.
Many thanks to all of you for all of the help provided!!

Glad it worked out.

---

And so am I. I don't understand why it should have been necessary: normally I'd put that down to a bad peering gateway between two backbone carriers, somewhere between your local ISP and Berkeley. But that should affect all three computers equally....

I wouldn't worry about it. HTTP 1.0 should be plenty good enough for SETI.

Thanks to you all for the guidance.
I just hate it when gremlins attack. :)
Take care!