zabbix_agentd.conf ファイルは以下のようになっています。
それから、zabbix_agent.confとかありますけれど修正の必要はありませんよね。（わからなくて）

# This is config file for zabbix_agentd
# To get more information about ZABBIX, go http://www.zabbix.com

############ GENERAL PARAMETERS #################

# List of comma delimited IP addresses (or hostnames) of ZABBIX servers.
# No spaces allowed. First entry is used for sending active checks.
# Note that hostnames must resolve hostname->IP address and
# IP address->hostname.
#<----------: MDF ytomi
#Server=127.0.0.1
#-----------: MDF ytomi
Server=(Zabbixサーバ側マシンのIPアドレス)
#---------->: MDF ytomi

# Server port for sending active checks

#ServerPort=10051
#<----------: ADD ytomi
ServerPort=10051
#---------->: ADD ytomi

# Unique hostname. Required for active checks.
#<----------: MDF ytomi
#Hostname=localhost
#-----------: MDF ytomi
Hostname=（エージェント側本マシンのマシン名）
#---------->: MDF ytomi

# Listen port. Default is 10050

#ListenPort=10050
#<----------: ADD ytomi
ListenPort=10050
#---------->: ADD ytomi

# IP address to bind agent
# If missing, bind to all available IPs

#ListenIP=127.0.0.1
#<----------: ADD ytomi
ListenIP=127.0.0.1
#---------->: ADD ytomi

# Number of pre-forked instances of zabbix_agentd.
# Default value is 5
# This parameter must be between 1 and 16

StartAgents=5

# How often refresh list of active checks. 2 minutes by default.

#RefreshActiveChecks=120

# Disable active checks. The agent will work in passive mode listening server.

#DisableActive=1

# Enable remote commands for ZABBIX agent. By default remote commands disabled.

#EnableRemoteCommands=1

# Specifies debug level
# 0 - debug is not created
# 1 - critical information
# 2 - error information
# 3 - warnings
# 4 - information (default)
# 5 - for debugging (produces lots of information)

DebugLevel=3

# Name of PID file

#<----------: MDF ytomi
#PidFile=/var/tmp/zabbix_agentd.pid
#<----------: MDF ytomi
PidFile="C:\Program Files\Zabbix_Agent\zabbix_agentd.pid"
#<----------: MDF ytomi

# Name of log file.
# If not set, syslog will be used

#<----------: MDF ytomi
#LogFile=/tmp/zabbix_agentd.log
#-----------: MDF ytomi
LogFile="C:\Program Files\Zabbix_Agent\zabbix_agentd.log"
#---------->: MDF ytomi

# Maximum size of log file in MB. Set to 0 to disable automatic log rotation.
#LogFileSize=1

# Spend no more than Timeout seconds on processing
# Must be between 1 and 30

Timeout=3

####### USER-DEFINED MONITORED PARAMETERS #######
# Format: UserParameter=<key>,<shell command>
# Note that shell command must not return empty string or EOL only
#UserParameter=system.test,who|wc -l
### Set of parameter for monitoring MySQL server (v3.23.42 and later)
### Change -u<username> and add -p<password> if required
#UserParameter=mysql.ping,mysqladmin -uroot ping|grep alive|wc -l
#UserParameter=mysql.uptime,mysqladmin -uroot status|cut -f2 -d":"|cut -f1 -d"T"
#UserParameter=mysql.threads,mysqladmin -uroot status|cut -f3 -d":"|cut -f1 -d"Q"
#UserParameter=mysql.questions,mysqladmin -uroot status|cut -f4 -d":"|cut -f1 -d"S"
#UserParameter=mysql.slowqueries,mysqladmin -uroot status|cut -f5 -d":"|cut -f1 -d"O"
#UserParameter=mysql.qps,mysqladmin -uroot status|cut -f9 -d":"
#UserParameter=mysql.version,mysql -V