Depending on whether you need a full OS installer or just the update package, your sources will vary: Windows Vista Service Pack 2 - Microsoft Update Catalog
While Microsoft has officially ended support for Windows Vista, there are still several ways to obtain the ISO or standalone installers safely. Official and Secondary Download Sources windows vista service pack 2 iso download
For users looking to maintain or revive legacy systems, finding a is a critical first step. Service Pack 2 was the final major update for Vista, bringing essential stability, security, and hardware compatibility improvements that made the OS far more usable than its initial release. Depending on whether you need a full OS
Windows Vista Service Pack 2 Standalone for x64-based Systems (KB948465) - All Languages, Windows Vista, Service Packs, 8/24/2010, Microsoft Update Catalog bringing essential stability