You may be interested in using Winrpe without SSL as the NRPE communication flows through other secure channels like vpns or port forwarders.

• On the monitored host with Winrpe: Update file etc\xinetd.d\nrpe and add option -n to server_args parameter:

# default: on
# description: NRPE
service nrpe
{
type = UNLISTED
flags = REUSE
port = 5666
socket_type = stream        
wait = no
user = SvcXinet
server = /bin/nrpe
server_args = -n -c /nrpe.cfg --inetd
log_on_failure += USERID
disable = no
# only_from       = <ipaddress1> <ipaddress2> ...
}

• On the monitoring host: Add the option -n to your check_nrpe commands.