Vista : TrustedInstaller CPU Utilisation

NOTE : This article only applies for Vista Ultimate
TrustedInstaller.exe is used by the windows service called "Windows Module Installer" (Or rather is the service) Says it has something to do with updating windows, so uninstalling or disabling it could cause some updates to fail. I wouldn't remove or delete the file itself. Simply set the service to start manualy.
Step A : Stop it loading at Startup
1. Start Menu ->Run

2. Type msconfig and select Services section

3. Remove the tick from the box next to Windows Module Installer

Step B: Set it to Manual to prevent issues...
1. Right click taskbar and select properties

2. Select Start Menu tab and choose Customise..." button

3. In the list, check "Display administrative tools" and click apply and click ok

4. Now go to Start Menu -> Program Files -> Administrative tools -> Services

5. Look in the list for the service "Windows Module Installer"

6. Double click and look for the dropdown menu stating "Startup Type"

7. Select "Manual" from the list

8. Click Apply, click ok

9. Now restart

Your CPU will not be utilised on boot for the first five (5) minutes anymore!