FIX: "HTTP 400 - Bad request" error message in the .NET Framework 1.1

When you run the Microsoft .NET Framework 1.1, and then you visit a URL that contains a second colon (":"), you receive the following error message:For example, the following URL generates this error message:Note You may also receive this error message if the URL contains the following characters:

Service pack information

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:

To browse URLs that contain the characters that are mentioned in the "Symptoms" section, obtain the latest service pack for the Microsoft .NET Framework 1.1. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Registry information

Important If you enable this fix, you increase the attack surface of the application. You should not enable this fix unless the application requires it.

After you install the service pack, set the following registry key to enable the fix:

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section. This problem was first corrected in the .NET Framework 1.1 Service Pack 1.

For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base: