I am going to start working for my MCSE and I need to have my own little network at home I can mess with. I really don't want to have to buy and support 5 machines so I am looking into VM workstation5. Has anyone used this? If so how many virtual machines can I run at once? If I create a virtual machine for Windows XP do I have to have a seperate Win XP serial for each virtual client? Say I want a Win NT client - Do I have to have a full package of Win NT with cd key? Just wondering. Even so it would be cheaper than all the hardware.