BOINC Manager-Connection Failed
"not able to connect to a BOINC client."

I searched a lot of threads and checked a lot of stuff looking for an answer.

Then I discovered that in Windows, this was often a name resolution problem, i.e. the name of the machine or the name "localhost" was not bound to the network card as an IP address. This seems to work well for me:

Just do this once to bind "localhost" to the network card:

From Control Panel>Network Connections:
Right-click on your connection: Select Properties.
Highlight Internet Protocol, select Properties.
Select Advanced, click on Import LMHOSTS.
Exit all dialog boxes and reboot.

This binds the IP address using the lmhosts file in windowssystem32driversetc that's part of any default Windows installation.

Whenever the connection fails, first try this:

From BOINC Manager, select the Advanced menu tab.
Select "Select computer...
For Host name, enter 127.0.0.1, press OK.

Doesn't work all the time, but often prevents need for reboot.

Chris