utmpdump: 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/utmpdump - from package: sysvinit-tools

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

On Debian possible default full paths are:

/usr/bin/utmpdump - from package: util-linux

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

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