zwgc: 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 Debian possible default full paths are:

/usr/bin/zwgc - from package: zephyr-clients

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

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