Websites not working on webserver

I have 3 ASP websites stored on my webserver. Recently 2 of them stopped working. The 3 websites are sharing the same website folder on IIS with different bindings so when 1 website is down usually the 3 of them will be down. I think the issue is with the DNS. The DNS records are stored on my server. When loading the website www.fk-sales.com on the browser an error will appear immediately so I'm thinking it's not running any ASP code on the IIS website. I've tried restoring Windows Server, resetting the router and disabling the firewall although this does not solve the issue.

Any help would be appreciated