i upgraded quite some time ago to widows 8 pro from win 7 no problems to date anyway i now have a popup in the bottom of my screen Activate windows i go to activate and i get error 0xc004f074 (even though windows has been activated for ages) i have tried slui3 route as well

As per the problem description, I understand that you get 0xc004f074 error code while activating your Windows 8 operating system. Windows was upgraded from Windows 7 to Windows 8 pro on this computer and Windows 8 was activated.

I would appreciate if you can provide us the following information to help us understand the issue better.

Which Windows 7 version was installed on this computer prior to Windows 8 pro upgrade?

Is this computer connected to a domain network? Or does this computer work as a server?

Error code 0xC004f074 appears due to support version mismatch between KMS client and KMS host Machine or there is a time difference between KMS Client and KMS host machine.

Refer the article below for more information on this.

When trying to activate you get 0xC004F074 with description “The Key Management Server (KMS) is unavailable”

https://support2.microsoft.com/kb/974998?wa=wsignin1.0

Note:The article applies to Windows 7, but applicable to the present scenario.