We've spent a long time poking, prodding and stress-testing these three operating systems, but it's still remarkably difficult to pick the outright best of Windows XP and Vista. XP is mature, still current enough to be compatible with most recent hardware and software, and a good all-round performer. But Vista fights back with a much better feature-set, especially in key areas such as security and error handling. On balance, we prefer XP for basic systems and would move to Vista only as hardware needs demanded – but that's a fine line to tread.
The good news is that you won't have to spend long agonising over the whole 'XP or Vista?' decision, because Windows 7 generally outdoes them both. Microsoft really does appear to have learned its hard-taught lessons and, while it hasn't fixed everything, the latest incarnation of Windows does show significant improvements over its predecessor – impressive for a pre-release version. The finished Windows 7 can only be better, and it should finally give long-standing XP fans a reason to upgrade.