ld86: 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/ld86 - from package: dev86

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

On Debian possible default full paths are:

/usr/bin/ld86 - from package: bin86

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

Error in other languages:
ld86: bevel nie gevind nie
ld86: comandă negăsită
ld86: comando não encontrado
ld86: commande introuvable
ld86: command not found
ld86: käsku ei ole
ld86: không tìm thấy lệnh
ld86: komanda nerasta
ld86: Kommando nicht gefunden.
ld86: kommandot finns inte
ld86: komut yok
ld86: nie znaleziono polecenia
ld86: níor aimsíodh an t-ordú
ld86: no se encontró la orden
ld86: no s'ha trobat l'ordre
ld86: opdracht niet gevonden
ld86: parancs nem található
ld86: perintah tidak ditemukan
ld86: príkaz nenájdený
ld86: příkaz nenalezen
ld86: команда не найдена
ld86: командата не е открита
ld86: 命令找不到
ld86: コマンドが見つかりません