Hello developers at Parallels, I have noticed that the option to open links and mail related things from the Windows VM in Mac are available at all times, even when the isolate Windows from Mac option is enabled. I think this behaviour is concerning as this defeats the security that an isolated virtual machine should provide. Here is a screenshot showing that the option to open in Mac are available, even when the VM is supposed to be isolated. If you enable open in Mac then links are indeed opened in the Mac, despite the VM is "isolated". I think that the Parallels client should ignore any "request" to open in Mac, when the isolate Windows from Mac option is enabled. If you don't have Parallels Tools installed on your Windows VM then the option to open in Mac isn't available in the first place, however this does not provide an ideal user experience. Mainly because the screen resolution can't change dynamically.