I appreciate your input. Good try, but now I'm certainly stumped. Wasted hours on this, with no luck. Here's my log of all I tried, with details of your suggestion in Item #7:
04/21/13 Microsoft Updates didn't work, I suspect may have been caused by cCleaner!
Running Windows XP Pro-SP3 desktop with IE8 (which is the latest version for XP) and Norton Internet Security.
- Tried to install four updates: KB2820917, KB2808735, KB2813170, and KB2813345. All four failed to download, with Error Code 0x80070005.
- In Internet Options, deleted history, allowed activeX controls to run without prompt, and unchecked “Do not save encrypted pages to disk.”
I turned off Popup Blocker & Smart Screen Filter.
I ran SuperAntiSpyware full scan.
Tried again. Same error.
- I went to: http://support.microsoft.com/find-solutions/windows/windows-xp/
Clicked on: Fix performance, errors or crashes
And then clicked on: Windows Update
Which led to: http://support.microsoft.com/mats/windows_update
Did not help.
- I contacted MS Phone Support. Rep guessed it is either malware or permissions issues. He could not help more than that.
- I ran command:
secedit /configure /cfg %windir%\\repair\\secsetup.inf /db secsetup.sdb /verbose
This placed a log in "C:\WINDOWS\security\logs\scesrv.log".
Tried again. Did not work.
- Then I noticed that my Windows 7 laptop can no longer connect to this desktop via Remote Desktop Connection. It had been able to do so before I ran into these problems.
- I went to http://support.microsoft.com/kb/KB971058 , for Windows Update failures, as Arachibutyrophobia had kindly suggested.
I ran the popup.
I set a restore point.
I clicked on Let me fix it myself
Ran Steps 1,2,3 and 5 successfully. Step 4 is not applicable.
In Step 6, I got three errors:
o Dialog Box: mshtml.dll was loaded, but the DllRegisterServer entry point was not found. This file can not be registered.
o Dialog Box: LoadLibrary("wucltux.dll") failed - The specified module could not be found.
o Error on the Command screen: LoadLibrary("wuwebv.dll") failed - The specified module could not be found.
In Step 7, I got an error on the Command screen: The following command was not found: reset winsock.
Ran Steps 8 and 9.
Step 10 is not applicable.
Clicked on Step 11, which brought me to http://support.microsoft.com/kb/949104
Ran the popup.
Tried again, and got same problem.
- Reset IE 8 to all original settings.
Tried again, and now was offered the original four updates plus a new one, KB2817183, which worked. But the four old ones failed to download, with the same error code 0x80070005.
- Downloaded 32-bit MS Safety scanner from http://www.microsoft.com/security/scanner/en-us/default.aspx
Turned off Norton firewall, double-clicked MSERT.exe, and ran full scan.
It found OpenCandy spyware and removed it partially.
So I ran Malwarebytes full scan, which found no malicious items.
Windows Updates still fail with the same error code.