Wednesday, April 25, 2007

Vista Update KB930178 Fails

An update failed on my new Vista installation with error 0xc015001a. "c015" seems to refer to Component Based Servicing (CBS), which is the tool that applied the update. 001a generally means it couldn't create or delete something. C:\Windows\WindowsUpdate.log shows more detail about the error, including the directory where it unpacked the distribution. Running Process Monitor from Sysinternals shows that TrustedInstaller.exe failed to create a file in the unpacking directory, C:\Windows\SoftwareDistribution\Download\\inst.

I tried turning off Symantec Antivirus. I tried turning off User Access Control (UAC) in the Users and Groups control panel.

When it finally worked, the system state was the following:
- Logged on as THE administrator.
- UAC was off
- Changed properties on the SoftwareDistribution\Download\ directory so that it, and its children, were no longer read only.
- applied the patch during shutdown