So in regards to blocking specific countries you will need to acquire the ip address range using 3rd party sites but for example if I was in another country and wanted to block the united states I could use code like this:
This code was generated using a 3rd party site (https://www.countryipblocks.net)
Once you have the code generated you can place it within your .htaccess file, I have included a link to more info regarding that if you are not familiar.
(ip address range in example is not complete due to character restrictions and does not work)
<Limit GET POST> deny from 126.96.36.199.0 allow from all </Limit>
It should work the same. You would still have an web.config file in a WordPress installation on Windows, which acts like a .htaccess does on a Linux system. You should be able to edit said file just like an .htaccess, add the code, and it should work. For further help you may have to contact support.
Once your issue is resolved,
please be sure to come back and click accept for the solution