We 1500 clients which managed through SCCM 2007. out of 1500 workstations 300 are showing failed to install updates with following error code from scanagent.log. Also the error state messge id is 11756
 -Scan Failed for ToolUniqueID={CACC0F54-E6B6-40AA-8BCD-81A1C7BE2918}, with Error=0x8024400d

Error From WUAHanlder.log

OnSearchComplete - Failed to end search job. Error = 0x8024400d.

I searched over google for this issue and found some thing related with Group policy, but there is no exact cause and solution found for this. Could you please some one help me on this.

1. On the affected machine, disable the SCCM Agent. To do this, you can run the following commands: Disable the Service --> sc config CcmExec start= disabled Stop the Service  net stop CcmExec
2. Ensure that the following policy is not enforced on the system: User Configuration\Administrative Templates\Windows Components\Windows Update\Remove access to use all Windows Update Features
Check this first in the local system policy (you can pull this up using gpedit.msc Local Group Policy Editor). After that, please run RSOP.msc and ensure that the policy is not configured either. This will give you information from domain policies too. If the policy is enabled please either remove the policy or disable it.
3. Restart the Automatic Updates service.
4. Now, from the command line, run the following command: Configure Proxy  proxycfg.exe p WSUS SERVER FQDN
By doing this, we are configuring WinHTTP so that server access in upper case is also bypassed.
At this point, we need to test an update scan. Since the SMS Host Agent service is disabled and stopped, we wont be able to use the agent to run the scan. In this case, we would need to run a scan using the command below:
wuauclt /resetauthorization /detectnow
Check Windowsupdate.log for the outcome of the testing
How to Bypass Proxy server for testing purpose using proxycfg untility. (More details http://msdn.microsoft.com/en-us/library/windows/desktop/ms761351(v=vs.85).aspx). Also find the registry entries you can check for bypass list HKEY_LOCAL_MACHINE\ SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Connections\ .

checked with above options not resolved the issue, and it is reporting different error code now:  Failed to find updates with error code 80244019