Windows XP (known as Whistler) Build 2202 is the Early Build and it's Post-RTM for Windows 2000, it was Released on 2000-02-02. The "SD" in the build tag refers to a new code management system that Microsoft were developing ("Source Depot"). This build was likely compiled as a test of this system. It is unclear whether this is a post-RTM Windows 2000 build or an Alpha build of Windows XP (codename Whistler).