see: 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/see - from package: mime-support

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

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