aterm-xterm: 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/aterm-xterm - from package: aterm

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

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