WinCommand: 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/WinCommand - from package: afterstep

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