Kiel, Germany - Windows Vista is the safest Microsoft operating system available, according to an online test conducted by the Association of German Network Security.

The test covered 225,000 PCs in Germany. Around 5.5 per cent of f computers using the Vista system had security problems. People using computers with the Windows XP operating system reported problem rates of 12 per cent. Even more problems were reported with computers using Windows 98, ME, and Windows 2000 - around 20 per cent.

The test did not include alternative operating systems such as Linux or Mac OS. (dpa)