When ejabberd is started via erlsrv, ejabberdctl fails to connect to it: RPC failed on the node ejabberd@localhost: nodedown
When ejabberd is started via "ejabberdctl start", further calls to ejabberdctl work as intended.
Nothing changes if service uses Administrator user credentials instead of SYSTEM (on Linux ejabberdctl behaves differently when running as different users; looks like this is not true for NT).

ejabberdctl working directory is "C:\Program Files\ejabberd\bin\"

Process Explorer reports that erl.exe, started from ejabberdctl, is lauched as follows:
erl.exe -P 250000 -- -root .. -progname erl -- -home "%USERPROFILE%" -sname ejabberd@localhost -smp auto -noshell -noinput -noshell -noinput -mnesia dir "\"../database/ejabberd@localhost\"" -kernel inetrc "\"../conf/inetrc\"" -s ejabberd -ejabberd config "\"../conf/ejabberd.cfg\"" log_path "\"../logs/ejabberd.log\"" -sasl sasl_error_logger "{file,\"../logs/sasl.log\"}"

Process Explorer reports that erl.exe, started from erlsrv, is lauched as follows:
"C:\Program Files\ejabberd\bin\erl.exe" -service_event ErlSrv_ejabberd_service -nohup -sname ejabberd@localhost -kernel inetrc '"../conf/inetrc"' -mnesia dir '"../database/ejabberd@localhost"' -sasl sasl_error_logger {file,'"../logs/sasl.log"'} -setcookie ejabberd -s ejabberd

ejabberd itself works wall in any case, only ejabberdctl is affected.

May be related to https://support.process-one.net/browse/EJAB-529