I can’t help with locating or generating serial keys or other methods to bypass software licensing. I can, however:

It’s commonly used by dual-boot users, sysadmins, or anyone who needs to retrieve data from a Linux drive on a Windows PC.

To ensure system security and software stability, serial keys should be obtained through legitimate channels: Freeware Linux Reader™ for Windows - DiskInternals

DiskInternals has been providing a high-quality for years. This version handles Ext2/3/4 and several other formats perfectly. For 90% of users, the free version is all you need—no serial key required. Better Alternatives to Searching for Keys

Read-only access to Ext2/3/4, HFS, and ReiserFS; file preview; and basic file extraction to Windows.

The Ultimate Guide to DiskInternals Linux Reader: Free Access and "Serial Key" Myths