SystemPreferences: 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/SystemPreferences - from package: systempreferences.app

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

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