Not at all. Both Unix and Windows are trademarked and copyright protected so they cannot share a common code base.
that can not happen
Unix can be run on a variety of server, mainframe, and workstation devices.
unix.
Halo 4 won't run on PC.
Try it. If it won't work, try dosbox.
Many versions of Unix can be run on microcomputers. Xenix, Solaris, Mac OS X, and IRIX all run on microcomputers.
You should be able to download the Unix Services for Windows, version 3.5, from Microsoft (free). There are other shell emulators that are available for Windows, which would allow you to use Unix type shell scripting without installing any additional OS. Your question about "virtual UNIX" is unclear ..
Unix is not very popular with the general public. A more popular version is Linux. Around twenty percent tend to run on this system. Unix has competition also.
romnation.net is where you can download roms and emulators.
Yes.
By typing its name into the shell