After months of waiting leaks and Betas, Microsoft Windows Vista Service Pack 1 is finally here officially, with all sorts of performance, usability and security tweaks, this upgrade is a must have (read full changelog document here).

The Vista SP1 upgrade is just 65 MB's in size and will be pushed to Windows Update in April categorized as an - optional update, However if you don't mind the extra size, you can download the full standalone installer with all language packs from Microsoft's website