Is there any way to registered my pre-installed microsoft windows 8 ?

and,

If i installed windows from an ISO file downloaded from microsoft website how can I activate again. 

• Edited by Kabir Humayun Sunday, February 15, 2015 8:22 AM

YOu can use the product key included. 

https://support.microsoft.com/kb/950929?wa=wsignin1.0

Hi Kabir,

For your first question ,we just need to reactivate the system with the product key .
What is a product key?
http://windows.microsoft.com/en-hk/windows-8/what-is-product-key

We can refer to the following link to get the product key .
How To Find Out Your Windows 8 Product Key
http://social.technet.microsoft.com/wiki/contents/articles/20346.how-to-find-out-your-windows-8-product-key.aspx

For your second question ,you need another product key the activate the ISO image .
In a word ,one product key is used to activate one system image.

Best regards