Thank you very much for your reply.

You may be able to work around the limits of hosting one domain on a single server using Virtual Machine. You could load VM on your server, install a server OS and configure it as a DC for your secondary domain.

Although this is technically possible, with two domains on one server your taking a risk since a single server failure now disables two domains instead of one. And not sure how DNS, authentication traffic and a host of other AD required services are going to function since all of your traffic is going to have to come into one physical box. I’d suspect you will have some performance issues at very least. If your going to attempt this do some research first and try it out in a test environment first!

My suggestion is lobby for your company to purchase another server to host your second domain. I think in the long run your going to find that administration headaches will be far less with two boxes than what you could be in for attempting to run from one.

Good luck!