Sign in error - incorrect user or password

Hello there
Any clue why all of sudden the sql services stop in our production server which caused JDE services stop working and we encounter the error stated above when users try login.

Is there any reason caused sql service stops?

Thanks

AD

Have you looked at the SQL server error log yet? There are many reason it may have stopped but its pretty good about logging them. Also what version of SQL and is this clustered?

It is none cluster and we have SQL Server 2005.
The logs does not give too much info.

Must be something else may be other application inhouse has long script etc.

Thanks

AD