kopete: 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/kopete - from package: kdenetwork

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

On Debian possible default full paths are:

/usr/bin/kopete - from package: kopete

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

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