kst2: 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/kst2 - from package: kst

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

Error in other languages:
kst2: bevel nie gevind nie
kst2: comandă negăsită
kst2: comando não encontrado
kst2: commande introuvable
kst2: command not found
kst2: käsku ei ole
kst2: không tìm thấy lệnh
kst2: komanda nerasta
kst2: Kommando nicht gefunden.
kst2: kommandot finns inte
kst2: komut yok
kst2: nie znaleziono polecenia
kst2: níor aimsíodh an t-ordú
kst2: no se encontró la orden
kst2: no s'ha trobat l'ordre
kst2: opdracht niet gevonden
kst2: parancs nem található
kst2: perintah tidak ditemukan
kst2: príkaz nenájdený
kst2: příkaz nenalezen
kst2: команда не найдена
kst2: командата не е открита
kst2: 命令找不到
kst2: コマンドが見つかりません