I just won against a Windows Update issue on XP that had me quite puzzled. The error that I was getting with both Microsoft and Windows Update was "Error Number: 0x8024402C The website has encountered a problem and cannot display the page you are trying to view." and "Error Number: 0x8024402C The website has encountered a problem and cannot display the page you are trying to view."
Looking at the WindowsUpdate.log file under "c:\Windows\" I found a line that says
"WARNING: SendRequest failed with hr = 80072ee7. Proxy List Used <proxy.company.com:1234> Bypass List Used : <null>"
The proxy however in IE has been removed so that there is no proxy under Tools > Internet Options > Connections > LAN Settings. Here is the catch, if you open a command prompt and type in "proxycfg" you will see that the proxy listed in the WindowsUpdate.log error is still in the registry. To clear this type in the following
net stop wuauserv
net start wuauserv
Once you have cleared that cached proxy MS update and Windows Update will work again. MS has a document on this proceedure on their website.