Server application Unavailable_ Base application when publishing Web site

I'm referring to this http://www.cublog.cn/u/8180/showart_171293.html.

Server Application Unavailable
The Web application you are attempting to access on this Web server is currently unavailable. Please hit the ' Refresh ' button in your Web browser to retry your request.
Administrator Note:an error message detailing the cause of this specific request failure can is found in the application Event log of the Web server. Please review this log entry to discover what caused this error to occur.

The reason for this error is that the. NET Framework 2.0 program is placed in the same application pool as the. NET Framework1.1 (or 1.0) program (by default into the DefaultAppPool pool), that is, by the same worker process: W3wp.exe is managed, and a single worker process cannot manage different programs (or different versions of programs) at the same time. If you first access a page of the. NET Framework 1.1, the worker process loads and manages the 1.1 version of the assembly, and then accesses the Web Program page of the. NET Framework 2.0, and the Server application unavailable error comes out. Conversely, if you access the Web program for 2.0 before the w3wp.exe of the default application pool has been started (when the application set has already loaded the. NET framework2.0 Web assembly), and then access the 1.1 or 1.0 Web Program page, the same will also occur. "The server application is not available" such as Chinese prompts. (You can end up with the previous w3wp.exe for testing.) ）

Workaround: Create a new application pool in IIS, and then select your virtual directory based on. NET framework2.0, point "Properties", select the newly created application pool in the application pool and click OK.