-- Integrated security error occurs because SQL Server cannot find a SQL Server account for the NT account.
Solution: To resolve this problem, check the NT account trying to access the database and make sure it maps to the correct SQL Server account.
If the mapping is okay, check the account name and make sure the SQL Server account is a valid account. For example, SQL Server does not allow the same characters in account names that NT does. If you map the NT account IUSR_Server1 to the SQL Server IUSR_Server1account, users cannot log on because the underscore is not a valid character in a SQL Server account name.
-- Make sure Integrated security is turned off.
To make sure that SQL Server does not use Integrated security, set its security option to Standard. The following steps demonstrate how to make this change for SQL Server 6.5.
To change SQL Server to use Standard security,
Start SQL Server Setup from the SQL Server folder on the Programs menu.
Click Continue until the Microsoft SQL Server Options dialog box is shown.
Click the Set Security Options option button.
Click Continue.
Click the Standard entry.
Click OK.
Continue through the remaining screens, accepting the defaults.