You will need to use you web browser (Internet Explorer) to download the nst-1.2.3.iso.gz ISO image from the Files area of the Network Security Toolkit project at SourceForge. If you are feeling lucky, you might be able to begin the download by clicking here.

After downloading the ISO you will need to uncompress it using either the free gzip utility or popular WinZip utility.

You will then use a CD burning package like Roxio or Nero to burn the ISO image to a CDR or CDRW.