below from MSDNSymptoms When you attempt to extend a web site based on SharePoint Team Services from Microsoft,the following error message appears: Logon failed for user 'Administrator'. Reason: Not associated with a trusted SQL Server connection (Error code: 18452). The SharePoint team Web site is not extended, even though you are using the Administrator's account and the correct password. Cause This error message can occur if the SQL Server is using Windows only authentication. SharePoint Team Services requires SQL Server authentication and uses a system account to log on to the SQL Server. Resolution To correct this problem, change the SQL Server authentication method to use both SQL Server and Windows. To do this, follow these steps: Start the SQL Server Enterprise Manager. Right-click the name of the server running SharePoint Team Services, and then click Properties on the shortcut menu. Click the Security tab. In the Authentication section, click SQL Server and Windows. Under the Startup service, select System. Click OK. If you are prompted to stop and restart the SQL server, click Yes. Extend the SharePoint team Web site by using the 'sa' account.
When you attempt to extend a web site based on SharePoint Team Services from Microsoft,the following error message appears: Logon failed for user 'Administrator'. Reason: Not associated with a trusted SQL Server connection (Error code: 18452).
The SharePoint team Web site is not extended, even though you are using the Administrator's account and the correct password. Cause
This error message can occur if the SQL Server is using Windows only authentication. SharePoint Team Services requires SQL Server authentication and uses a system account to log on to the SQL Server. Resolution
To correct this problem, change the SQL Server authentication method to use both SQL Server and Windows. To do this, follow these steps: Start the SQL Server Enterprise Manager.
Right-click the name of the server running SharePoint Team Services, and then click Properties on the shortcut menu.
Click the Security tab.
In the Authentication section, click SQL Server and Windows.
Under the Startup service, select System.
Click OK.
If you are prompted to stop and restart the SQL server, click Yes.
Extend the SharePoint team Web site by using the 'sa' account.
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSSQLServer\MSSQLServer\LoginMode REG_DWORD, 11---Windows认证模式
2---SQL和Windows认证模式