No Network Adapters - ESX 5.5 Installation

Hi,

I have an 5 year old ACER ASPIRE AM5640-E5520A machine running PROXMOX for the last 3 years.I am trying to install ESX 5.5 and received an error stating "No Network Adapter".I tried to do a quick google search and failed to find relevant information on the network card and drivers related to it.

I am hoping to have some guidance in enabling the network card. Pls let me know.

Thanks