Techie

The credentials you provided for the SQL server Agent service are invalid. To continue, provide valid account and password for the SQL server Agent Service.

Today, I have decided to install SQL SERVER 2008 on my PC. All was going fine until I came to server configuration page/tab. I is not proceeding further and asking me to insert correct credential to move to the next page. If you are also getting the same error then just enter following data in Account name and password:

Account Name : "NT AUTHORITY\NETWORK SERVICE "
Password : Blank

I hope this will resolve your issue.

To solve this issue
Go to registry editor
Start --> Run --> Regedit
Expand the keys
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\90\Tools\ShellSEM

Export the ShellSEM key, delete it, install SQL 2008 and then restore it.