My computer claims that my windows is not genuine when it very much is

i searched around google on how to fix it and came across the command prompt slmgr -ato

and a message pops out saying "Error: product not found"

what does this mean and what do I do?

Hi,

Which version for Windows are you using? Please check if the following KB article applies:

http://support.microsoft.com/en-us/kb/2008385

Since this issue is more related to Windows Client, if you need further assistance, I'd recommend you post your question in the following forum:

https://social.technet.microsoft.com/Forums/en-US/home?category=WinPreview2014%2Cw7itpro%2Cw8itpro%2Cwindowsvistaitpro%2Cwindowsxpitpro%2Cwindowsintune

The reason why we recommend posting appropriately is you will get the most qualified pool of respondents, and other partners who read the forums regularly can either share their knowledge or learn from your interaction with us. Thank you for your understanding.

Steve Fan
TechNet Community Support