This morning I was upgrading an existing ASP.Net application on Windows 2008 R2 server. Previously it was using an application pool that was using ASP.Net 2.0 framework. Since I had compiled the application with .Net 4.0 framework, I need to switch in IIS 7.5 for application to use application pool for ASP.Net 4.0. As soon as I switched to using ASP.Net 4.0 framework in application pool, I got the following error.

404 - File or directory not found.
The resource you are looking for might have been removed, 
had its name changed, or is temporarily unavailable.

That did not make sense for a moment because I was just using the web application and how can I get 404 error just by switching ASP.Net version in application pool. After digging around in Microsoft Knowledge base and IIS7 documentation, I found that the issue is related to ISAPI filter for ASP.Net 4.0 not being enabled in IIS. Here is what you need to do see what is enabled and what is not enabled for ISAPI and CGI in your server.

From IIS Manager, click on top node of your server in left pane. You will see feature view as shown in the image below.

You can see that only ISAPI filters enabled for my server are for ASP.Net 2.0. The ones for ASP.Net 4.0 are not available. Just enabled those for ASP.Net 4.0 and you should be all set to roll.

Other day I was installing a DotnetNuke site on Windows 2008 R2 server. I followed all the usual steps of creating a new web site in IIS7.5 on Windows 2008. When I tried to access the site, I ended up with the following error.

HTTP Error 401.3 - Unauthorized

You do not have permission to view this directory or page because of the access control list (ACL) configuration or encryption settings for this resource on the Web server.

In the past I had run into this problem and I knew that it has something to do with application pool and accounts associated with that pool. The error message clearly tells that it has something to do with file permissions on the folder where the web site was physically present. Here are some of the common causes of this sort of error when you configure a new web site on Windows 2008 IIS7.5.

Check Application Pool

Most important is that you need to check what Application Pool is being used for your site and make sure that that account being used by that pool has appropriate access rights on the folders and files. In Windows 2008 R2 there are some important changes related to accounts that are used for IIS application pools. Most of us who come to Windows 2008 R2 environment, get stumped by the fact that it may not be Network Service account that is used for your web site process.

First thing first, we need to figure out what application pool we are using and how we can change it. Here are my earlier posts where I described these steps.

• How to find Application Pool Of web site on Windows 7
• How to configure Application Pool in IIS in Windows 7

Security Account Used By Application Pool

This piece of information is at heart of solving the error with access control list. When you bring up advanced settings dialog box for the application pool, you will find the following value that tells you the account used by your application pool.

Select the button next to that name and it will bring up following diaolog box where you can change the account settings for your pool identity. You can select system defined accounts from the dropdown or you can select a custom account that you have created for your site.

Diagnosing The Error

So far I have discussed cause and remedies of the error that you got. Now let's see how you can diagnose the issue to really find out what account was trying to access the site files that ended up in access denied error.

I always keep my super tool Process Monitor tool handy on all my development as well as production servers. You can download it from SysInternals site. Fir it up and acces the site. After you get the error, capture the trace and then look for ACCESS DENIED error. I will not go into details about how to effectively use this tool with filters and all to get to the correct information quickly. There you will be able to see windows account that was trying to access the files. Now you can go to site fclder and configure appropriate access rights for the account and you are good to go!

In earlier post I discussed how to find application pool of your web site or web application in Windows 7 and Windows 2008. Next set of questions that I get asked right off the bat are:

• Where are all applicaton pool in IIS in Windows 7 and Windows 2008?
• How to change settings of an application pool in IIS in Windows 7 and Winds 2008?

Here is step by step procedure to find what all application pools you have in IIS7.

• Start IIS Manager console.

• Look in the tree in left hand side pane. There you will find a node named Application Pools. Click on this link.

  

• In the center pane, you will see list of all application pools that have been create on your machine.

  

• Select the pool that you want to inspect or configure. In the right hand pane you will find the list of actions that you can perform on the pool.

  

• Click on Advanced Settings to all the details of your application pool configuration. This is where you can make changes to pool configuration.

  

In IIS7 and higher one of crucial points in web site configuration is Application Pool. A lot of developers who are new to IIS7 and higher IIS management console, ask a very basic question, How do I find Application Pool for the site?. Here is answer to this question.

• Bring up IIS Managager console from Administrative tools.

• Select the web site or web application, for which you find to configure Application Pool, in left hand side pane.

• In the right hand side pane, click on Basic Settings link.

• It will bring up following view, where you can see your application pool for your web application.

  

• Click on Select button if you want to see all the pools that are available to you. This is where you can change Application Pool for your application.

After installing Windows 2008 Server or for that matter any flavor of Windows server, you will quickly realize that using Internet Explorer on that machine can be a real pain. Well Microsoft has every good intention about keeping the security very tight on the server and the default options set for Internet Explorer on Windows 2008 Server are too tight. I am not going to debate about security issues related to Internet Explorer.

I wanted to install Google Chrome browser just to avoid dealing with tight settings for IE. Well to start with I had to use IE anyways so I could access Google site to get installer. So I did and added Google.com to trusted sites list. So I started install of Google Chrome. After 3-4 seconds, installer threw an error that application is not properly formatted. I was like what application is not formatted. I seriously doubt that it had anything to do with Chrome installer being corrupt. From the dialog box I clicked on the button to see the details of the error and found the following message.

PLATFORM VERSION INFO
 Windows 			: 6.0.6001.65536 (Win32NT)
 Common Language Runtime 	: 4.0.30319.1
 System.Deployment.dll 		: 4.0.30319.1 (RTMRel.030319-0100)
 clr.dll 			: 4.0.30319.1 (RTMRel.030319-0100)
 dfdll.dll 			: 4.0.30319.1 (RTMRel.030319-0100)
 dfshim.dll 			: 4.0.31106.0 (Main.031106-0000)

SOURCES
 Deployment url : http://dl.google.com/update2/1.2.183.29/GoogleInstaller_en.application?
 Server		: downloads

ERROR SUMMARY
 Below is a summary of the errors, details of these errors are listed later in the log.
  * Activation of http://dl.google.com/update2/1.2.183.29/GoogleInstaller_en.application resulted 
   in exception. Following failure messages were detected: 
 + Your Web browser settings do not allow you to run signed applications.

ERROR DETAILS
 Following errors were detected during this operation.
  * [8/16/2010 7:17:04 PM] System.Deployment.Application.InvalidDeploymentException (Manifest)
   - Your Web browser settings do not allow you to run signed applications.
   - Source: System.Deployment
   - Stack trace:
   at System.Deployment.Application.ApplicationActivator.BrowserSettings.Validate(String manifestPath)
   at System.Deployment.Application.ApplicationActivator.PerformDeploymentActivation(Uri activationUri, 
   Boolean isShortcut, String textualSubId, String deploymentProviderUrlFromExtension, 
    BrowserSettings  browserSettings, String& errorPageUrl)
   at System.Deployment.Application.ApplicationActivator.ActivateDeploymentWorker(Object state)

The key to this error message was Your Web browser settings do not allow you to run signed applications.. Well security settings on IE was preventing the installer to complete the installation. So here is what you can do if you run into issue with installation of any applications on Windows 2008 Server that you download from internet.

• Goto the application web site.
• Click in Download button or link or what ever way the site provides to install the application. When you get the dialog box with options to Run or Save, Choose to Save it on your disk.
• Now goto folder where you saved the installer and launch it from there. This should now run without being under the context of IE security.

As usual, you just have to be careful with what you download and install on your server.

After I installed Windows 7 x64 device driver on my Windows 2008 Server x64 laptop, I looked my wireless network connection utility and noticed that my wireless connection was not working. I looked in device manager and saw that there was no problem with driver installation. There was no yellow mark against the wireless card device. Then I went into Manage Network Connections windows. The icon was there for wireless connection but it was in Disabled. I tried to enable it and it won't enable. It kept getting back into Disabled and every time I tried to enabled a windows error message will pop up asking to check for solution online. I decided to look in the event log and found there were plenty of errors with following message.

One thing was clear that network utility was trying to do some action and it was failing in WLanApi.dll. This dll has implementation of Wireless Network APIs. Then it clicked that on Windows 2008 Server, Wireless LAN Service feature is not installed by default. So simple solution is to goto Server Configuration wizard to launch features window and add Wireless LAN Service feature and finish the installation and wireless card will work fine.