pterm: 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/pterm - from package: putty

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

On Debian possible default full paths are:

/usr/bin/pterm - from package: pterm

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

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