SQL Server 2008R2 Logon failed The SS error log indicates the following at a frequency of 2 to 3 times per hour:


  Logon failed for login 'NT AUTHORITY\NETWORK SERVICE' due to trigger execution. [CLIENT: ]


There is no logon trigger. How do I discover what trigger is causing the problem since the error log does not say?

(This is on a Win 7 Pro computer running SS 2008r2 developer.)
Have you considered using a trace to audit logins and/or triggers.

in case you find a trigger using this particular login the following post - Login failed due to trigger execution underlines the security context (see Microsoft answers) in which logon triggers are executed.

Hope this helps.