Maybe you should clarify a bit more. AIX is an operating system itself, so no it doesn't "run on Windows". Now there are emulators that you can install on a Windows box that can gain access into an AIX server via various types of sessions, like telnet, ftp, x sessions, etc. Some of these emulators include DCSi ETerm, Hummingbird Exceed, Attachmate, and others. Or you can do just a straight telnet from your C-prompt to get to command line login. And then there is web access into AIX Web Servers like for Oracle and such.
Yahoo lists several emulators in there software search, plus there are many sites on the Internet, search on AIX Terminal Emulators.
Hope this helps.