How to Fix an HTTP 400 Bad Request Error

1. Go to the Microsoft Download Center and download the .NET Framework 1.1 Service Pack 1 (see Resources).
2. Save the file and double-click on it when it completes the downloading process. Follow any instructions on the screen to install it.
3. Go to 'Start' > 'Run' and type in the command 'regedit.' Wait for the Registry Editor to load.
4. Go to 'Edit' > 'Find.' Type 'HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\ASP.NET' and press 'Enter.'
5. Right-click on the file name 'VerificationCompatibility' when it loads. Select 'Modify.'
6. Type '1' for the 'ValueData' and press 'OK.'
7. Close the windows and restart your PC.