I’ve been hit with these two errors repeatedly in the last two days. The fix is tedious but feasible. If you have tried everything else you’ve found on the net and couldn’t get rid of them, here is what you can do. Get a copy of “process monitor” from http://technet.microsoft.com/en-us/sysinternals/bb896645.aspx. Install and run it. Then go to Filter menu and select “Filter…” item. Here click on the first button on the top left (should say Architecture initially) and select “Result”. Leave the next one (should say ‘is’) alone and type “ACCESS DENIED” without the quotes (and notice the space in the middle) into the text box. Click on the last button (should say Include initially) and select “Exclude”. Finally click the “Add” button, then click OK at the bottom.
Now open windows update from Start menu. On process monitor do a clear ie Edit|”Clear Display” or CTRL+X and click on “Check for updates” in Windows update. Here you need to carefully monitor the event list in the ProcMon window and find the items where TrustedInstaller.exe is causing “ACCESS DENIED” errors. Then you need to go into Registry and change the permissions of those keys to give SYSTEM account full access. Then run “check for updates again” till you no longer get an error in Windows update. Sometimes if your system is really messed up, you need to delete some of the packages completely from the registry and also from %WINDIR%\servicing\Packages directory and run Windows update again. It’s a tedious and iterative process. If you have any problems you can email me for questions.