kinfocenter: 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/kinfocenter - from package: kdebase

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

On Debian possible default full paths are:

/usr/bin/kinfocenter - from package: kinfocenter

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

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