Update downloads but will not install

this is the message I get in windows log:
Log Name: System
Source: Microsoft-Windows-WindowsUpdateClient
Date: 20/04/2012 22:22:00
Event ID: 20
Task Category: Windows Update Agent
Level: Error
Keywords: Installation,Installation
User: SYSTEM
Computer: roy-one
Description:
Installation Failure: Windows failed to install the following update with error 0x80070643: Update for Microsoft .NET Framework 4 on Windows XP, Windows Server 2003, Windows Vista, Windows 7, Windows Server 2008, Windows Server 2008 R2 for x64-based Systems (KB2468871).

How can I find and delete this update as it tries to install every time I try to power off. Thanks for any help going

How long do you wait for this update to install? I ask because .NET Framework updates are notorious for taking some time to install and will prompt this warning if you try to shut down before the update has completed its installation.

Also, if you switch your computer off before the update has installed, it will try and install again when you reboot.

You won't find it to delete it because it hasn't installed. If you do need to find updates that have installed, you need to navigate to Start>Control Panel>Programs>Uninstall A Program>View Installed Updates.

You might also want to download and run the System Updates Readiness Tool (SURT) in an effort to solve your problem.

Download: System Update Readiness Tool for Windows 7 for x64-based Systems (KB947821) [February 2012] - Microsoft Download Center - Download Details

seavixen32 said:

How long do you wait for this update to install? I ask because .NET Framework updates are notorious for taking some time to install and will prompt this warning if you try to shut down before the update has completed its installation.

Also, if you switch your computer off before the update has installed, it will try and install again when you reboot.

You won't find it to delete it because it hasn't installed. If you do need to find updates that have installed, you need to navigate to Start>Control Panel>Programs>Uninstall A Program>View Installed Updates.

You might also want to download and run the System Updates Readiness Tool (SURT) in an effort to solve your problem.

Download: System Update Readiness Tool for Windows 7 for x64-based Systems (KB947821) [February 2012] - Microsoft Download Center - Download Details

thanks for the reply. I have waited for an hour at a time for this update before powering of the computer.
I will have a look at the tool you have posted and hope this will solve the problem

OK, do keep us updated or post back if you need further help.