opvizor can help you extremely easy to find out about virtual machines still running on MS Windows 2003. Keep in mind that Windows 2003 is end of support this June and you might need to schedule some tasks before you can remove your W2k3 VMs. Very often it's not about the OS itself, but the OS infrastructure services like Active Directory that causes the pain. Of course also applications that are running and have not touched for years.
Less than 2 month left, it's critical to create your battle plan.
We created a short video just to give you an idea about how fast and easy you can work with our analysis results: https://vimeo.com/125612710