We have a windows app running on terminal machines, and use Parallels Client to run the app remotely from either Mac client or Windows client. In the windows app, we would like to know if the client is connected through a Windows or Mac. We've been checking the existence of c:\windows\system32, if so, we assume it's a windows. However, as we tighten up security rules, the windows app no longer have read access to that folder, so the check on that folder no longer work. Is there anything else we can do to check the client OS? We don't need to know any detail, just need to know if it's Windows or not.