public static OSVersionInfo getInstance() {
if (versionInfo == null) {
OSVERSIONINFO info = new OSVERSIONINFOW();
info.dwOSVersionInfoSize = OSVERSIONINFOW.sizeof;
if (!Extension.GetVersionExW((OSVERSIONINFOW) info)) {
info = new OSVERSIONINFOA();
info.dwOSVersionInfoSize = OSVERSIONINFOA.sizeof;
Extension.GetVersionExA((OSVERSIONINFOA) info);
}
versionInfo = new OSVersionInfo();
versionInfo.buildNumber = info.dwBuildNumber;