fvwm2: 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/fvwm2 - from package: fvwm

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

On Debian possible default full paths are:

/usr/bin/fvwm2 - from package: fvwm

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

Error in other languages:
fvwm2: bevel nie gevind nie
fvwm2: comandă negăsită
fvwm2: comando não encontrado
fvwm2: commande introuvable
fvwm2: command not found
fvwm2: käsku ei ole
fvwm2: không tìm thấy lệnh
fvwm2: komanda nerasta
fvwm2: Kommando nicht gefunden.
fvwm2: kommandot finns inte
fvwm2: komut yok
fvwm2: nie znaleziono polecenia
fvwm2: níor aimsíodh an t-ordú
fvwm2: no se encontró la orden
fvwm2: no s'ha trobat l'ordre
fvwm2: opdracht niet gevonden
fvwm2: parancs nem található
fvwm2: perintah tidak ditemukan
fvwm2: príkaz nenájdený
fvwm2: příkaz nenalezen
fvwm2: команда не найдена
fvwm2: командата не е открита
fvwm2: 命令找不到
fvwm2: コマンドが見つかりません