syndaemon: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/syndaemon - from package: xorg-x11-drv-synaptics

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/syndaemon - from package: xserver-xorg-input-synaptics

You may install the required package with command apt-get install {package}

Error in other languages:
syndaemon: bevel nie gevind nie
syndaemon: comandă negăsită
syndaemon: comando não encontrado
syndaemon: commande introuvable
syndaemon: command not found
syndaemon: käsku ei ole
syndaemon: không tìm thấy lệnh
syndaemon: komanda nerasta
syndaemon: Kommando nicht gefunden.
syndaemon: kommandot finns inte
syndaemon: komut yok
syndaemon: nie znaleziono polecenia
syndaemon: níor aimsíodh an t-ordú
syndaemon: no se encontró la orden
syndaemon: no s'ha trobat l'ordre
syndaemon: opdracht niet gevonden
syndaemon: parancs nem található
syndaemon: perintah tidak ditemukan
syndaemon: príkaz nenájdený
syndaemon: příkaz nenalezen
syndaemon: команда не найдена
syndaemon: командата не е открита
syndaemon: 命令找不到
syndaemon: コマンドが見つかりません