pptpsetup: 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/sbin/pptpsetup - from package: pptp-setup

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

On Debian possible default full paths are:

/usr/sbin/pptpsetup - from package: pptp-linux

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

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