My computer is set to use automatic updates from Windows Update. So when SP1 for Windows 7 came out, I didn't even think about installing it… Windows Update will take care of it for me. But sadly I was mistaking.
After two months I realized that the service pack had not been installed. So I downloaded the service pack from Microsoft Download Center, and tried to install it. But I got an error: "the update is not applicable to your computer".
Googling around, I found that I needed some updates I needed before installing the service pack. I checked Windows Update and indeed the updates were missing. When I checked for updates Windows Update stated that my computer is up to date. Weird. But I didn't gave up… Found the updates from the download center and ran them – but with the same error.
In the event viewer under Setup log I found this error: "Windows update could not be installed because of error 2149842967". Googling it results to nothing. in the System log I found this error: "The TrustedInstaller service failed to start due to the following error: The system cannot find the file specified". The weirdness keep's on going…
TrustedInstaller is in fact a service called "Windows Modules Installer" which is responsible for various processes in the operating system. One of them is Windows Update installations and Windows features installations. Checking the services I so that the WMI service has gone missing. I also tried to open the Windows Features (turn Windows Features on or off in Programs or Features from the Control Panel), but it came out empty. I also checked if the TrustedInstaller.exe exists in c:\windows\servicing folder, but the file wasn't there.
I searched how to recover the service, but the best answer I found was to format and reinstall windows. Eventually I found a similar problem in the Windows Vista forums which offered this solution:
- Take the TrustedInstaller.exe from another computer. WATCH OUT: if you have 64 bit version make sure you take the file from a computer with the same version and vice versa. It is not possible to copy the file directly to the c:\windows\servicing folder due to security issues, but it is possible using an installation disk of your Windows 7
- Put the file in a temporary folder on your computer
- Boot the computer with your Windows 7 installation disk
- Click Next in the language selection screen
- DO NOT click Install now. Click on repair installation
- Select the installation and click next
- Select the Command Prompt option
- copy the TrustedInstaller.exe to c:\windows\servicing
- Exit and restart the computer normally
- Run Command Prompt as Administrator (type cmd in the start menu –> right click on cmd.exe –> Run as administrator –> Ok)
- Type: cd\windows\servicing
- Type: TrustedInstaller.exe
- After it finish running go to the services screen (type services.msc and enter)
- Find a service called "Windows Modules Installer"
- Right click –> Start
- From the command prompt type: SFC /scannow
- If no issues are found, restart and check for updates in Windows Update
After I did all that I found out that I had about 50 updates to install before installing Service Pack 1. I installed all of them and the service pack.
The lesson: Everybody lies – even Windows Update