checkpc: 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/sbin/checkpc - from package: lprng

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

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