FlyOOBE (Flyby11) 2.3.833 Final reviews
FlyOOBE can bypass Microsofts official CPU, TPM, and Secure Boot requirements.
However, Windows 11 24H2 requires POPCNT and SSE4.2 instructions, which cannot be bypassed by any tool. I recommend running FlyOOBE - version 2.3 includes a compatibility checker that will warn you if your AMD Athlon processor supports these instructions.
If you see a checkmark next to CPU POPCNT and SSE4.2, the upgrade should work.
Many thanks.
You can only downgrade to Windows 10 within the 10 days of your upgrade. For example, if you upgraded to Windows 11 on 1 September, 2025, then you can downgrade within 10 days. If you want to downgrade on 25 September, 2025, you can't.
You can rollback to Windows 10 by going to Settings > System > Recovery and pick the Go Back option. After these 10 days, i think that you need to make clean install of Windows 10.