gconftool-2: 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/gconftool-2 - from package: GConf2

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

On Debian possible default full paths are:

/usr/bin/gconftool-2 - from package: GConf2

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

Error in other languages:
gconftool-2: bevel nie gevind nie
gconftool-2: comandă negăsită
gconftool-2: comando não encontrado
gconftool-2: commande introuvable
gconftool-2: command not found
gconftool-2: käsku ei ole
gconftool-2: không tìm thấy lệnh
gconftool-2: komanda nerasta
gconftool-2: Kommando nicht gefunden.
gconftool-2: kommandot finns inte
gconftool-2: komut yok
gconftool-2: nie znaleziono polecenia
gconftool-2: níor aimsíodh an t-ordú
gconftool-2: no se encontró la orden
gconftool-2: no s'ha trobat l'ordre
gconftool-2: opdracht niet gevonden
gconftool-2: parancs nem található
gconftool-2: perintah tidak ditemukan
gconftool-2: príkaz nenájdený
gconftool-2: příkaz nenalezen
gconftool-2: команда не найдена
gconftool-2: командата не е открита
gconftool-2: 命令找不到
gconftool-2: コマンドが見つかりません