User ' IIS apppool\.net v4.5 Classic ' login failed.

After I finished writing the project with vs2013+sqlserver08 under the win8.1 system and moved to another win8.1 system (with vs2010+sqlserver08 installed), the following error occurred when I hung the URL into IIS:

Solution:

1, when configuring the URL, the application pool select version corresponding model:

2, click on the application pool under the IIS root node in the list to the right to select the version that was selected in the application pool when the URL was just configured, right-click "Advanced Settings" drop-down found "identity" selected as LocalSystem.

User ' IIS apppool\.net v4.5 Classic ' login failed.