well, try install Window Agent 2.0 and see if it solves the problem:
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some of the forum suggest this method:
1. Make sure you are logged in as an Administrator (if you are not the Administrator, then log in as an Administrator and try Windows Update again).
2. Make sure your firewall is not blocking the Update site and check any pop up stopper programs.
3. Now check in IE tools\Manage Add-ons (Win XP SP2 only) making sure that "WuWebControlClass" is enabled. (Select "Add-ons that have been used by Internet Explorer" in the "Show:" drop down list)
4. You may also wish to check "C:\WINDOWS\Downloaded Program Files" to see if anything is corrupted there.
5. Make sure you accepted the Microsoft Trust Certificate:
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To turn on automatic updating of trusted root authority certificates:
1. In Control Panel, open Add or Remove Programs
2. Click Add/Remove Windows Components.
3. Select the Update Root Certificates check box.
4. Click Next, and then click Finish.
Note: To open Add/Remove Windows Components, click Start, click Control Panel, click Add or Remove Programs, and then click Add/Remove Windows Components.
6. Check security settings, make sure they are not set too high
7. Delete cookies and temp files
8. Re-register these files, by clicking Start, Run and typing:
REGSVR32 wuapi.dll
REGSVR32 wuaueng.dll
REGSVR32 atl.dll
REGSVR32 wucltui.dll
REGSVR32 wups.dll
You should receive a successful message after each one. Try Windows Update Again. If that hasn't helped you may need to re-register some more files:
net stop cryptsvc
regsvr32 softpub.dll
regsvr32 wintrust.dll
regsvr32 initpki.dll
regsvr32 dssenh.dll
regsvr32 rsaenh.dll
regsvr32 gpkcsp.dll
regsvr32 sccbase.dll
net start cryptsvc
You should receive a successful message after each one.
As an addition, if you received 0x80070005 - "access denied" to the registry keys involved in Windows Update, then look below:
Run the WGA-Diagnostic Tool (named MGAdiag):
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Check points:
Make sure the Administrators group has Full Control permissions to the Auto Update registry key.
1. Use an account that has administrative credentials to log on to the Windows XP computer.
2. Click Start, click Run, and then type the following command: regedit
3. Click OK.
4. Navigate to the following key in the registry: "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\AutoUpdate"
5. Right-click the Auto Update folder, and then click Permissions.
6. Make sure that the Administrators group has Full Control.
Also check especially if the WindowsUpdate.log file will also read errors 0x80070005 and 0x80080005
Locate the following key:
"HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate".
On the menu, click Edit. Click Permissions.
For Administrator and System, select the Allow check boxes next to Full Control and Read permissions.
NOTE: In certain instances, these check boxes are grayed out. Ensure all accounts have appropriate permissions.
Click Apply, Click OK, Close the Registry Editor. Restart the system.
If you're using Windows XP Pro make sure it hasn't been disabled by Group Policy:
1. Start/Run/gpedit.msc
2. User Configuration/Administrative Templates/Windows Components/Windows Update.
3. In the right pane, double click, Remove access to all Windows Update Features and set it to the default "not configured"
Another workaround is to use Regmon and see for what keys get "Access Denied", or Restore the permission back to default
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How to reset security settings back to the defaults - WinXP Professional
Regmon is a Registry monitoring utility that will show you which applications are accessing your Registry, which keys they are accessing, and the Registry data that they are reading and writing - all in real-time:
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