If still the same issue persists then try the below methods.
Method 1. For the error message, please see the article below as it seems to be a known issue.
MS08-069: Description of the security update for XML Core Services 4.0: November 11, 2008 http://support.microsoft.com/kb/954430
Method 2. To work around this problem, manually install the security update from the Microsoft Download Center, and then click Ignore when the error message is displayed.
Download standalone package of this update from the link below and install. http://support.microsoft.com/kb/973688
Method 3. To confirm that the installation was successful, verify that the version of the Msxml4.dll file in the %SystemRoot%\System32 folder is 4.20.9870.0.
See if this helps.
If this doesn't help, you may try resetting Windows update components and reinstall it again.