Windows 8 x64 RTM - works out of the box. WinBox is not dependant on endless numbers of frameworks and it should run on any Windows box or a Linux/Mac box with Windows app emulation such as wine. Make sure you scan your winbox.exe with Windows Defender or any other antivirus, as it may be infected by something else.
winbox 2.2.18 not working under Windows 8 (x64). Mikrotik Winbox Loader starts but when I try to connect to router nothing happends. Loader window dissapears and next but router configuration window do not appear