Fixed: IIS ASP.NET Server Application Unavailable Error

My IIS suddenly does work with asp.net today, It shows me "Server Application Unavailable Error". I have tried "<WinDir>\Microsoft.NET\Framework\<Ver>\aspnet_regiis.exe -i" and "regsvr32 "<WinDir>\Microsoft.NET\Framework\<Ver>\aspnet_isapi.dll" but it does not work. After google a bit, I found it maybe user sercurity issue, So I go to the Control Panel -> Event Viewer and I found this:

aspnet_wp.exe could not be started. The error code for the failure is 80004005. This error can be caused when the worker process account has insufficient rights to read the .NET Framework files. Please ensure that the .NET Framework is correctly installed and that the ACLs on the installation directory allow access to the configured account.

The solution for this is:

1. Right click "My Computer" and select "Manage".
2. Expand the "Local Users and Groups" inside "System Tools" node.
3. Within "Users" folder, right click "ASPNET" and select "Properties".
4. In the "General" tab, uncheck "Account is locked out" and "Account is disabled".
5. Restart the IIS by using iisreset command. Worker Process should be launched now without any issue.

Another solution from Microsoft:

FIX: ASP.NET does not work with the default ASPNET account on a domain controller