Does SQL Server not exist or access is denied?

Some time ago, an ASP. Net project using SQL Server 2000 occasionally experienced such a problem:

• SQL Server does not exist or Access denied.

SQL Server and project run on one machine. This problem often occurs after a project is used for a while. After restarting SQL Server, everything will return to normal, but after a while, the same problem will occur. Finally, we checked the connection string in Web. config and replaced it with the connection string of another normal project. We found such an interesting thing. The first and second connection strings are written in this way.

Problematic connection string: uid = sa; Pwd =; database = xxxxxx; workstation id = (local)
Normal connection string: uid = sa; Pwd =; database = xxxxxx; server = (local)

The previous project ownerProgramThe workstation ID is mistakenly used to configure the SQL server address field. If you change it to a server or data source, there is no problem, at least till now.

Although the problem has been solved, there are some questions.

• Why does the system not immediately encounter problems without setting the address of SQL Server? Instead, this problem occurs only after a period of time. Incredible.
• Why does restarting SQL server temporarily recover to normal.