There are indeed a few options for what you want to do here.
Probably the easiest would be to set up vnc access on the mac (found under sharing in system preferences), and use tightVNC (free) from windows to connect. With tightVNC viewer, you will need to change the encoding from tight to raw (at least whne I just tested connecting to my mac server) tight produces an error. When the tightVNC viewer connection screen comes up, click on options, and change encoding to raw. If you still recieve errors, use the Allow JPEG Compression slide bar and move to the left untill no more errors.
There are indeed other solutions which involve setting up a himatchi server, or using something like xrdp http://www.xrdp.org/ if you would like to go that route. If you are on the same network, I would bet the tightVNC route might be the best option. I have not tested and RDP connection to Win7 running on VM on a mac, so I am not sure if that will work, although based on jvincilione's response, you just need windows running in the vm.
There are also web based services like TeamViewer and aammyy admin which will require keystrokes on both sides with free versions.
HTH
