Hi,
Thank you for posting your query on Microsoft Community.
As per the description, I understand that you are unable to install MS dynamics prerelease version and getting an error to download KB 2390372.
I would first suggest you to check the KB in Windows update and see if it is available, try to install and check.
If the issue still persists, I would suggest you to re-post your query on TechNet forums as we have experts working on such type of issues and to help you in a better way.
Refer to the link:
https://social.technet.microsoft.com/Forums/windows/en-US/home?category=w8itpro
Hope this information helps. Please let us know if you need any other assistance with Windows in future. We will be happy to assist you.