You receive a 0x800A01AD error message while you access the Windows Update Web site (833766)

Error     IUENGINE       Determining machine configuration (Error 0x80040154: Class not registered)

RESOLUTION

To resolve this problem, you can try any one of the following methods.

Register the MSXML program files

To register the MSXML files, follow these steps:

Note You may not have installed the files that are listed in steps 4 and 6 on your computer. If you do not have one of these files, when you try to register the file, you will receive an error message that is similar to the following error message: You can ignore this error message and go to the next step.

Note Because there are several versions of Microsoft Windows, the following steps may be different on your computer. If they are, see your product documentation to complete these steps.

1. Click Start, point to All Programs, point to Accessories, and then click Command Prompt.
2. In the Command Prompt window, type Regsvr32 C:\Windows\System32\Msxml.dll, and then press ENTER.
3. When you receive the following message, click OK: DllRegisterServer in C:\Windows\System32\Msxml.dll DLL succeeded.
4. Type Regsvr32 C:\Windows\System32\Msxml2.dll, and then press ENTER.
5. When you receive the following message, click OK: DllRegisterServer in C:\Windows\System32\Msxml2.dll DLL succeeded.
6. Type Regsvr32 C:\Windows\System32\Msxml3.dll, and then press ENTER.
7. When you receive the following message, click OK: DllRegisterServer in C:\Windows\System32\Msxml3.dll DLL succeeded.
8. Close the Command Prompt window.

Install MSXML 3.0 SP4

To install MSXML 3.0 SP4, visit the following Microsoft Web site. Follow the instructions on the Web site to make sure that the service pack is installed correctly: