Please note that there is a known memory leak issue caused by MS. Read this KB
article: KB893317

I assume the user is familiar with WMI and has already set up his/her machine to compile WMI projects. if not, then check Set Up Delphi For WMI

List all network adapters on the local machine and check their status (enabled or disabled) using WMI in Delphi (can be modified to be used on remote machines as well)

 

Note: 15.08.2010 - fixed a memory leak

Source Code