import ctypes;

class OSINFO(ctypes.Structure):
 _fields_ = [
 ("dwOSVersionInfoSize",ctypes.c_long),
 ("dwMajorVersion",ctypes.c_long),
 ("dwMinorVersion",ctypes.c_long),
 ("dwBuildNumber",ctypes.c_long),
 ("dwPlatformId",ctypes.c_long),
 ("szCSDVersion",ctypes.c_char*128)
 ];

def GetSystemVersionString():
 kernel32 = ctypes.windll.LoadLibrary("kernel32.dll");
 os = OSINFO();
 os.dwOSVersionInfoSize = ctypes.sizeof(os);
 if kernel32.GetVersionExA(ctypes.byref(os))==0:
 return "Null Version";
 if os.dwPlatformId==1: #windows 95/98/me
 if os.dwMajorVersion==4 and os.dwMinorVersion==0:
 verStr = "windows 95";
 elif os.dwMajorVersion==4 and os.dwMinorVersion==10:
 verStr = "windows 98";
 elif os.dwMajorVersion==4 and os.dwMinorVersion==90:
 verStr = "windows me";
 else:
 verStr = "unknown version";
 elif os.dwPlatformId==2: #windows vista/server 2008/server 2003/xp/2000/nt
 if os.dwMajorVersion==4 and os.dwMinorVersion==0:
 verStr = "windows nt 4.0";
 elif os.dwMajorVersion==5 and os.dwMinorVersion==0:
 verStr = "windows 2000";
 elif os.dwMajorVersion==5 and os.dwMinorVersion==1:
 verStr = "windows xp";
 elif os.dwMajorVersion==5 and os.dwMinorVersion==2:
 verStr = "windows 2003";
 elif os.dwMajorVersion==6 and os.dwMinorVersion==0:
 verStr = "windows vista"; # or 2008
 elif os.dwMajorVersion>=0:
 verStr = "windows 7";
 else:
 verStr = "unknown version";
 else:
 return "unknown Version";
 return verStr+" build"+str(os.dwBuildNumber)+" "+ctypes.string_at(os.szCSDVersion);

if __name__ == "__main__":
 print(GetSystemVersionString());