20Windows Update AgentInstallationInstallation Failure: Windows failed to install the following update with error 0x80070003: Security Update for Windows XP (KB873339).
If new updates from the windows update web site are being installed successfully, but this particular update keeps failing, then you may try the following:
1. Start - Run
2. Type cmd then click OK
3. In the command prompt type the following command:
Net stop wuauserv
4. Using explorer delete the C:\Windows\Softwaredistribution and the C:\Windows\System32\Softwaredistribution folders.
5. In command Prompt type the following :
Net start wuauserv (Press Enter to Start Windows update services)
6. Try Windows Update again