See this Microsoft   - Article ID Q318378
How to Reinstall or Repair Internet Explorer and Outlook Express in
Windows XP

http://support.microsoft.com/default.aspx?scid=kb;[LN];q318378

I hope at least your I.E.  is usable to get to a plain vanilla web site.  e.g, it's working.

Some settings you ought to consider changing in order to get around the current problem:  But pls notice only 2 points (lines) are an experiment to get you over this episode.

In    I. E.  Tools >Internet Options > Advanced Tab >    (scroll down thru the list)

Under HTTP 1.1 settings --
Use HTTP 1.1      (ON / Selected)

and under Security :
Clear  (un-check)  the check box next to "Check for server certificate revocation" .   ( *OFF* )  

Clear (un-check) "Check for publisher's certificate revocation"    (*off*)        <<-this is the experiment)

Clear (un-check)  "Check for signatures on downloaded programs"   (* OFF* )     <<-(this too an experiment)

Use SSL 2.0       (ON / selected)
Use SSL 3.0       (ON)
Use TLS 1.0        (ON)

Apply changes.

Internet Explorer > main menu /Tools/Internet Options

Add these 2 entries to list of "Trusted Sites" -- the syntax as follows -- with the * wildcard:
*.windowsupdate.microsoft.com
*download.windowsupdate.com

Security Tab/ click on green icon Trusted Sites/click Sites button, add & apply change(s).

On the SECURITY Tab > Custom level button >  recheck all entries under Settings.
Review items that you may have disabled.

The Windows Update site  (as do many others)  uses scripting, VBS scripting, ActiveX.  So be aware to not turn them off.