olvwm-x-window-manager: 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/olvwm-x-window-manager - from package: olvwm

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

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