Do not expect any visible changes. Windows Server 2008 build 6003 remains functionally identical to 6002 . However, under the hood, the shift enables:
The build number was changed from to 6003 in April 2019 via update KB4493471 . windows server 2008 build 6003
Microsoft incremented the build number to resolve a technical limitation with : Do not expect any visible changes
For more technical documentation on this specific build transition, you can visit the Windows Server 2008 build 6003 page on BetaWiki or check the official Microsoft IIS installation guide for original hardware specs. Windows Server 2008 build 6003 - BetaWiki under the hood