desktop-effects: 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/desktop-effects - from package: desktop-effects

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

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