You would like to have a full hard disk installation of the Network Security Toolkit, but don't want to re-partition your hard disk.

You would simply like to try out a new Network Security Toolkit ISO distribution, but don't want to reboot your system. Using the free VMware Server or VMware Player, one can boot the Network Security Toolkit directly from the ISO file (you won't need to burn a disk).

You'd like to monitor the network traffic to and from a particular Windows machine, and you don't have the necessary hardware to tap into what's going across the Ethernet cable. By booting the Network Security Toolkit within a virtual machine on the Windows machine, you will be able to monitor the Ethernet traffic with tools such as wireshark, snort, ntop, etc.

You are doing development on a Windows machine and would like to use some of the features from the Network Security Toolkit without using an additional machine (the Network Security Toolkit makes it pretty easy to setup a web server or SQL database in these situations).