oeminst: 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 Debian possible default full paths are:

/usr/bin/oeminst - from package: argyll

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

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