After Windows Update none of the websites work anymore

On friday I installed windows updates - I guess this was not good at all.

All my websites return now error 500. So I checked Windows Event Viewer, there are two error logs:

Source: ASP.NET 4.0.30319.0
An error occured while trying to start an integrated application 
instance. 
Exception:System.Runtime.InteropServices.COMException
Message: An attempt was made to logon, but the network logon service was not started 
(Exception from HRESULT: 0x80070700 
StackTrace: at System.Web.Hosting.IProcessHostSupportFunctions.GetConfigToken(String appId)....

and the second one:

Source: IIS-W3SVC-WP
An Application has reported as being unhealthy. The worker process will now request a cycle. Reason given: ASP.NET application initialization failed.. The data is the error.
In Details there is the reason: ASP.NET application initialization failed. 00070780

I read, I need to check for the service "Netlogon". This service is state "Stopped" and when I'm trying to restart it, it still changes after "Starting" to "Stopped"

I already tried iisreset, restarting server,.. nothing helped. Any idea for a non-professional? My next step would be reinstalling windows on my v-server - I really don't want to.

Edit: I just remembered, I changed the administrators password on the hosters website. Seems like this destroyed my AD.