1.1 Why are Server control tags shown in the browser instead of the controls it represents?

This is because the server control tags were not converted into their respecting HTML element tags by ASP.Net. This happens when ASP.Net is not properly registered with IIS.

.Net framework provides an Administration utility that manages the installation and uninstallation of multiple versions of ASP.NET on a single machine. You can find the file in C:\WINNT\Microsoft.NET\Framework\v**\aspnet_regiis.exe

use the command: aspnet_regiis.exe -u ---> to uninstall current asp.net version.

use the command: aspnet_regiis.exe -i ---> to install current asp.net version.

1.2 How To Repair ASP.Net IIS Mapping After You Remove and Reinstall IIS?

To reassociate aspx file extensions with ASP.Net runtime, you'll have to run the utlity aspnet_regiis.exe -i
For more information refer to Microsoft Knowledge Base Article - 306005

1.3 Why do I get "HTTP 500" error (or "(DLL) initialization routine failed") in my browser?

This is because if you have the /3GB boot switch enabled, the ASP.NET worker process (Aspnet_wp.exe) does not start. For more information see Microsoft Knowledge Base Article - 320353

To create and set the "ASPNETENABLE3GB" environment variable as mentioned in the above article, right click MyComputer ->Properties->Advanced > Environment Variables > System variables > New.
Add the variable name in the top text box and the value in the lower textbox.

1.4 I have recently move my Web application from Windows 2k to Windows Server 2003. All works fine in Windows 2K but i am not able to view pages using Windows Server 2003?

You have to enable the ASP.NET in the Web Server Extensions list
From Start -> Settings -> Control Panel -> Administrative Tools -> double click IIS Manager.
Go to the Web Service Extensions tab, click Active Server Pages, then press the "Allow" button on the left.

1.5 What are the Best practices for side-by-side execution of Framework 1.0 and 1.1?

In ASP.NET, applications are said to be running side by side when they are installed on the same computer, but use different versions of the .NET Framework. The following article at www.asp.net details the practices that are recommended ASP.NET Side-by-Side Execution of .NET Framework 1.0 and 1.1

1.6 Can I have VS.NET and the Visual Studio 6.0 installed on the same machine?

Yes! VS.Net works with the .Net framework, while VS6.0 works with MFC or the Windows API directly, for the most part. They can be installed and run on the same machine without any considerations.

1.7 How should I check whether IIS is installed or not?

To verify if IIS is installed, go to your 'Add or Remove Programs' utility in the Control panel and click on the 'Add/Remove Windows Components' in the side menu.

On XP Pro and below, you should see an item called "Internet Information Services (IIS)". If this is checked, IIS should be installed.

On Win2K3, you'll see "Application Server". If this is checked, select it and then click 'Details'. Another form should open which will contain "Internet Information Services (IIS)". If it is checked, IIS should be installed.

1.8 In Visual Studio .NET, how do I create a new ASP.NET application for an existing ASP.NET project?

First create an IIS application using the IIS MMC. Then in Visual Studio .NET, use the "New Project In Existing Folder" project template (at the end of the template list). It will first ask you for the project name (use the same one you created for the IIS application). Click OK button. Then enter in physical folder location.

1.9 Why do I get the error message "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."?

By default, ASP.NET runs its worker process (Aspnet_wp.exe) with a weak account (the local machine account, which is named ASPNET) to provide a more secure environment. On a domain controller or on a backup domain controller, all user accounts are domain accounts and are not local machine accounts. Therefore, Aspnet_wp.exe fails to start because it cannot find a local account named "localmachinename\ASPNET". To provide a valid user account on the domain controller, you must specify an explicit account in the section of the Machine.config file, or you must use the SYSTEM account. For more details : FIX: ASP.NET Does Not Work with the Default ASPNET Account on a Domain Controller

1.10 In Visual Studio .NET, how do I create a new ASP.NET application which does not have a physical path under wwwroot?

You must first create an IIS application using the IIS MMC. Then in Visual Studio .NET, create a new ASP.NET application and give it the same name you used for the IIS application

1.11 Why do I get the "Unable to find script libruary 'WebUIValidation.js'" error ?

When you install the .Net framework on your web server, it installs some script files (including the above) under the root folder (usually "C:\inetput\wwwroot" if you do a default installation) . You can then find the above file at "C:\Inetpub\wwwroot\aspnet_client\system_web\1_1_4322", for example.

The above problem could happen if you reconfigured your web root directory to be a different one after you installed ASP.Net in your web server. If that is the case, then run 'aspnet_regiis -c' (utility is under %windir%\Microsoft.NET\Framework\v1.1.4322, for example) or copy over manually the above script files into a similar sub-directory below your current web root directory. Also, if you look at the error message in detail, you will notice where the file is supposed to be.

1.12 After installing .NET Framework SP1 the client side validations, or rather validator controls are not working?

The problem seems to be in the javascript file WebValidationUi.js in aspnet_client folder.The changes in that file prevent a page to be submitted. That could be the reason your javascript validations are not working. As a workaround, just copy the old WebValidateionUi.js over the new one.

1.13 How to Configure the ASP.NET Version to use for Each Application(developed using 1.0 or 1.1)?

To configure WebApp1 to use ASP.NET 1.0, follow these steps:

1. Click Start, and then click Run.
2. In the Open text box, type cmd, and then click OK.
3. At the command prompt, locate the following directory: WindowsDirectory\Microsoft.NET\Framework\v1.0.3705\
4. At the command prompt, type one of the following commands:
   • To Install ASP.NET 1.0 recursively
     aspnet_regiis -s W3SVC/1/ROOT/WebApp1
   • To Install ASP.NET 1.0 non-recursively
     aspnet_regiis -sn W3SVC/1/ROOT/WebApp1

1. Click Start, and then click Run.
2. In the Open text box, type cmd, and then click OK.
3. At the command prompt, locate the following directory: WindowsDirectory\Microsoft.NET\Framework\v1.1.4322\
4. At the command prompt, type one of the following commands:
   • To Install ASP.NET 1.1 recursively
     aspnet_regiis -s W3SVC/1/ROOT/WebApp2
   • To Install ASP.NET 1.1 non-recursively
     aspnet_regiis -sn W3SVC/1/ROOT/WebApp2

1.14 How to Configure Different Versions of an ASP.NET Application Running on the Same Web Server?

Here is an exerpt from the KB article: KB 816782

Find the ASP.NET Version Used for the Application View the script map for an ASP.NET application to determine the version of ASP.NET that the application uses. To view the script map for an ASP.NET application, follow these steps:

1. Click Start, point to Programs, and then click Control Panel.
2. Double-click Administrative Tools, and then double-click Internet Information Services (IIS).
3. Expand local computer, expand Web Site, and then expand Default Web Site.
4. Locate the folder that contains the ASP.NET application.
5. Right-click the folder that contains the ASP.NET application, and then click Properties.
6. Click the Directory tab, and then click Configuration. The Application Configuration dialog box opens.
7. Click the Mappings tab, and then select an ASP.NET application extension, such as .asmx or .aspx. The Executable Path column of the dialog box lists the path to the ASP.NET ISAPI version that the application uses. By default, the ASP.NET ISAPI is installed in %WindowsDirectory%\Microsoft.NET\Framework\%versionNumber%. The version number in the path indicates the version number of the ASP.NET ISAPI that the application uses. The ASP.NET ISAPI version determines the version of the runtime that the application uses.

1. Click Start, and then click Run. In the Open text box, type cmd, and then click OK.
2. At the command prompt, locate the following directory path:
   %WindowsDirectory%\Microsoft.NET\Framework\v1.0.3705\
3. Type the following command to configure the ASP.NET 1.0 application in IIS:

    

To remove ASP.NET 1.0 from this application, repeat steps 1and 2, and then type the following command:

1. Click Start, and then click Run. In the Open text box, type cmd, and then click OK.
2. At the command prompt, locate the following directory path:
   %WindowsDirectory%\Microsoft.NET\Framework\v1.1.4322
3. If ASP.NET 1.1 is not already registered, type the following command to register it: aspnet_regiis -ir Note The -ir option registers ASP.NET 1.1 without updating the scripts in IIS.
4. Type the following to configure the ASP.NET 1.1 application in IIS:

    

To remove ASP.NET 1.1 from this application, repeat steps 1 and 2, and then type the following command:

1.15 Why do I get error message "Internet Explorer cannot download MyPage.aspx from MyWebSite.com ..."?

This happens for example, whe you try to export data to excel from a datagrid.

The problem occurs if the server is using Secure Sockets Layer (SSL) and has added one or both of the following HTTP headers to the response message:

For more details refer PRB: Internet Explorer Is Unable to Open Office Documents from an SSL Web Site

1.16 Why do I get error message "Unable to start debugging on the web server. The server does not support debugging of ASP.NET or ATL Server applications. ..."?

You would get this error if the application mappings for ASP.NET file name extensions (such as .aspx) are not configured correctly in Microsoft Internet Information Services (IIS).

To resolve this go to C:\Windows Directory\Microsoft.Net\Framework\Version and type aspnet_regiis -i to configure the required application mappings correctly

For more information refer PRB: Cannot Debug ASP.NET Web Application