Cannot connect to SQL Server 2011 Denali

I'm running SQL Server 2011, aka Denali CTP 1 on my local computer. Yesterday I got an error message "Cannot connect to SQL Server Denali instance" when I tried to connect to SQL Server 2011 instance using SQL Server Management Studio (SSMS). Later when I digg the problem for a solution, I realized that SQL Server 2011 evaluation period has expired so I'll not be able to use the installed SQL2011 instance any more. The easiest way to work with Denali is uninstall SQL Server 2011 CTP and reinstall it again, of course if you are not patient enough to wait for the new SQL Server 2011 CTP 2.

Here is the error detail I got while trying to connect to SQL Server 2011 instance using SSMS

Cannot connect to Kodyaz\Denali
Additional information
A network-related or instance-specific error occured while establishing a connection to SQL Server. Ther server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified) (Microsoft SQL Server)

I opened the Services Management Console to see if the SQL Server 2011 service is running or not. The SQL Server service for SQL Server 2011 Denali was stopped. When I tried to start the sql engine service, I got the following error.

Windows could not start the SQL Server (Denali) service on Local Computer.
Error 1067: The process terminated unexpectedly.

I also checked the Windows Event Viewer for Application Logs to expecting to see a more detailed information about the error. I see a Server error with Event ID 17051 in number indicating that the trial period of the SQL Server 2011, Denali CTP1 has ended after 6 months. Here is the message related with the Event Id 17051 for SQL Server :
SQL Server evaluation period has expired.