gsetroot: command not found

Have You tried accessing the binary with the full path?

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/gsetroot - from package: gsetroot

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