pk11install: 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/pk11install - from package: coolkey

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

Error in other languages:
pk11install: bevel nie gevind nie
pk11install: comandă negăsită
pk11install: comando não encontrado
pk11install: commande introuvable
pk11install: command not found
pk11install: käsku ei ole
pk11install: không tìm thấy lệnh
pk11install: komanda nerasta
pk11install: Kommando nicht gefunden.
pk11install: kommandot finns inte
pk11install: komut yok
pk11install: nie znaleziono polecenia
pk11install: níor aimsíodh an t-ordú
pk11install: no se encontró la orden
pk11install: no s'ha trobat l'ordre
pk11install: opdracht niet gevonden
pk11install: parancs nem található
pk11install: perintah tidak ditemukan
pk11install: príkaz nenájdený
pk11install: příkaz nenalezen
pk11install: команда не найдена
pk11install: командата не е открита
pk11install: 命令找不到
pk11install: コマンドが見つかりません