Contrary to early internet rumors, . It is not Windows Server 2008 R2 (which is build 7600 series). Instead, 6003 is an artificially incremented build number deployed exclusively via ESU patches.
: Most scripts or apps that checked for "6002" as an identifier for Server 2008 SP2 required updates to recognize "6003" as the same platform. Platform Similarities windows server 2008 build 6003 patched
By 2017, Microsoft had begun the industry-wide transition from SHA-1 to SHA-2 code signing certificates. Windows Server 2008 SP2 originally did not support SHA-2 for update verification. Without a build number increment, the update stack could not reliably distinguish between a pre-SHA-2 system and a post-SHA-2 system. Contrary to early internet rumors,