Hello Pg,
You can’t turn the 90-day evaluation of Windows 11 IoT Enterprise LTSC 2024 into a fully licensed copy just by typing a key.
Evaluation media isn’t convertible by product key. Activation only works on the production SKU. To license it, install the production image of Windows 11 IoT Enterprise LTSC 2024 and activate with the channel that matches your license. OEM/OA3 (often auto-activates on hardware with an embedded key) or Volume Licensing (MAK/KMS). There is no retail key for IoT Enterprise.
A key for Windows 11 IoT Enterprise LTSC 2024 is the correct edition, keys for non-IoT or other LTSC versions won’t activate this SKU. The build number 26100.6901 is simply a serviced 24H2 build and doesn’t affect license validity.
Practical path:
Obtain the production ISO from your OEM or your licensing portal/reseller, perform a repair install (keep apps and files) or a clean install of that SKU, then activate with your MAK/KMS or let OA3 activation complete online. In Settings > System > Activation you’ll see Evaluation on the current image - if it says that, it won’t accept a commercial key.
I hope you find this helpful!
Best regards,
Finn