Service Pack 2 was a vital "clean-up" for Vista. Key improvements included:
Since Microsoft has officially ended support for Windows Vista, they no longer provide direct download links for the full OS on their main consumer pages. However, community-driven archives and official update mirrors still host these files: windows vista business service pack 2 download 32 bit iso
Added native support for VIA 64-bit CPUs and improved Bluetooth 2.1 connectivity. Service Pack 2 was a vital "clean-up" for Vista