I am trying to figure out why a Windows 2008 server became inaccessible in terms of RDP and access to a web application. The server was turned off and then on. Look at the event log at the time it went offline, I can't find anything. And looking at misc application logs, the system was running like normal after it went offline. It has to be said that by mistake the firewall was switched off earlier, so a lot of attempts had been done to access the SQL Server with the sa user as well as RDP login. But the attempts has been going on for days, so nothing new about that. Besides the event logs, is there anywhere else I can go to examine the cause of this?

I am also in doubt whether or not a DOS attack or similar would show up in the event log. From a log for a backup application running on this server I can see that an attempt was done to access a remote IP after the server went offline, but got no connection.