Organizations with volume licensing agreements can find keys in the Microsoft 365 admin center under the Volume Licensing sections. Locating a Key on an Installed System
Which of those would you like?
tab, and search for "Visual Studio .NET 2003" to claim your key. Pre-populated Keys visual studio 2003 product key
Here is a guide on how to handle the product key situation for Visual Studio 2003 legally and effectively. Organizations with volume licensing agreements can find keys