IIS server application unavailable Solution

Failed to execute request because the app-domain cocould not be created Solution
When you open an ASP. NET Website, if an error occurs, view the records in "Event Viewer". If warning information is found:

"Failed to execute request because the app-domain cocould not be created. Error: 0x80131902"

Failed to initialize appdomain:/lm/w3svc/1/root

Exception: system. configuration. configurationerrorsexception
Message: an exception of the type "system. configuration. configurationerrorsexception" is thrown.
Stacktrace: In system. Web. configuration. errorruntimeconfig. errorconfigrecord. system. configuration. Internal. iinternalconfigrecord. getlkgsection (string configkey)
In system. Web. configuration. runtimeconfiglkg. getsectionobject (string sectionname)
In system. Web. configuration. runtimeconfig. getsection (string sectionname, type, resultsindex index)
In system. Web. configuration. runtimeconfig. get_hostingenvironment ()
In system. Web. Hosting. hostingenvironment. startmonitoringforidletimeout ()
In system. Web. Hosting. hostingenvironment. initialize (applicationmanager appmanager, iapplicationhost apphost, iconfigmappathfactory configmappathfactory, hostingenvironmentparameters hostingparameters)
In system. Web. Hosting. hostingenvironment. initialize (applicationmanager appmanager, iapplicationhost apphost, iconfigmappathfactory configmappathfactory, hostingenvironmentparameters hostingparameters)
In system. Web. Hosting. applicationmanager. createappdomainwithhostingenvironment (string appid, iapplicationhost apphost, hostingenvironmentparameters hostingparameters)
In system. Web. Hosting. applicationmanager. createappdomainwithhostingenvironmentandreporterrors (string appid, iapplicationhost apphost, hostingenvironmentparameters hostingparameters)

Basically, this issue is most likely to occur on the first line of. NET Framework 2.0. The cause is unknown, but the following practices can solve this problem:

1. First open the "command window", cd c:/Windows/Microsoft. NET/framework/
2. Run "net stop W3SVC" on the command line"

3. cd c:/Windows/Microsoft. NET/framework/v2.0.50727/
4. "aspnet_regiis.exe-UA"

5. re-install. Net to IIS and execute "aspnet_regiis.exe-I"
6. cd c:/Windows/Microsoft. NET/framework/
7. Restart W3SVC and execute "Net start w3svc ".

OK...