xpmroot: 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/xpmroot - from package: fvwm

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

On Debian possible default full paths are:

/usr/bin/xpmroot - from package: fvwm

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

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