string OS()
	{
		string pack;

		OSVERSIONINFO version;
		version.dwOSVersionInfoSize=sizeof(version);
		if (GetVersionEx(&version))
		{
			if (version.dwPlatformId == VER_PLATFORM_WIN32s)
			//cout <<"Win32 ";
			return "Win32 ";
			else if (version.dwPlatformId == VER_PLATFORM_WIN32_WINDOWS)
			{
				if(version.dwMinorVersion == 0 && (strchr(version.szCSDVersion,'B')==NULL) && (strchr(version.szCSDVersion,'C')==NULL))
				//cout <<"Windows 95 ";
				return "Windows 95 ";

				else 
				if(version.dwMinorVersion == 0&& (strchr(version.szCSDVersion,'B')!=NULL))
				//cout <<"Windows 95 OSR 2 ";
				return "Windows 95 OSR 2 ";

				else 
					if(version.dwMinorVersion == 0 && (strchr(version.szCSDVersion,'C')!=NULL))
					//cout <<"Windows 95 OSR 2.5 ";
					return "Windows 95 OSR 2.5 ";

					else
						if(version.dwMinorVersion == 10 && (strchr(version.szCSDVersion,'A')==NULL))
						//cout <<"Windows 98 ";
						return "Windows 98 ";

						else if (version.dwMinorVersion == 10 && (strchr(version.szCSDVersion,'A')!=NULL))
						//cout <<"Windows 98 Second Edition ";  
						return "Windows 98 Second Edition ";
			}

			else if (version.dwPlatformId == VER_PLATFORM_WIN32_NT)
			{
				if (version.dwMinorVersion == 90)
				//cout <<"Windows Millenium Edition ";   
				//return "Windows Millenium Edition ";
				pack += "Windows Millenium Edition ";

				else if  (version.dwMajorVersion==5)
				{
					// entweder 2000 / XP / Server 2003 family
					if (version.dwMinorVersion == 0)
						//cout << "Windows 2000 ";
						//return "Windows 2000 ";
						pack += "Windows 2000 ";

					if (version.dwMinorVersion == 1)
						//cout << "Windows XP ";
						//return "Windows XP ";
						pack += "Windows XP ";

					if (version.dwMinorVersion == 2)
						//cout << "Windows Server 2003 ";
						//return "Windows Server 2003 ";
						pack += "Windows Server 2003 ";
				}

				else if(version.dwMajorVersion == 6)
				{
					//cout << "Windows Longhorn ";
					//return "Windows Vista ";
					pack += "Windows Vista ";
				}
			}

			else 
			{
				//cout <<"Windows Version unbekannt ";
				return "Windows Version unbekannt ";
			}  
			//	cout <<version.dwMajorVersion<<"."<<version.dwMinorVersion<<"."
			//		 <<(version.dwBuildNumber & 0xffff)<< " " <<version.szCSDVersion<<endl;

		//		Convert cvt;
				pack += cvt.IntegerToString(version.dwMajorVersion);
				pack += ".";
				pack += cvt.IntegerToString(version.dwMinorVersion);
				pack += ".";
				pack += cvt.IntegerToString((version.dwBuildNumber & 0xffff));
				pack += " ";
				pack += version.szCSDVersion;

				return pack;
		}
		else
		//cout <<"Die Windows Version kann nicht herausgefunden werden."<<endl; 

		return "Die Windows Version kann nicht herausgefunden werden. ";

	}

Was kann man hier noch verbessern?

bsp:

std::string Win32::GetOS()
{
    std::ostringstream	sstrOS;
    OSVERSIONINFO		os;

    ZeroMemory(&os, sizeof(OSVERSIONINFO));
    os.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);

    if(GetVersionEx(&os))
    {
		switch(os.dwPlatformId)
		{
	        case VER_PLATFORM_WIN32_NT:
					sstrOS << "Microsoft Windows NT";
	            break;
                       // usw usw 
	        default:
				return std::string("Unkown Microsoft Windows Platform");
	    }

		sstrOS << " " << os.dwMajorVersion;
		sstrOS << "." << os.dwMinorVersion;
		sstrOS << " Build: " <<  (os.dwBuildNumber & 0xFFFF);
    }
	else
		return std::string("Unkown Microsoft Windows Platform");

	return sstrOS.str();
}