kswitch: 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/lib/heimdal/bin/kswitch - from package: heimdal-workstation
/usr/bin/kswitch - from package: krb5-workstation

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

On Debian possible default full paths are:

/usr/bin/kswitch - from package: krb5-user

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

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