Re-downloading pending Windows updates

Update 2/26/2011: I neglected to mention that this fix is normally only needed for Windows XP. Windows 7 appears to have some auto-fix thing built-in, and I’ve never had this issue with Windows Vista.

I’ve often run into an issue where a Windows update is downloaded but can’t be installed. No matter how many times I tell it to install the update, Windows Update just says that the update failed. Very frustrating.

Luckily, I stumbled upon a solution, and it is so very simple:

1. Temporarily stop the Automatic Updates service.
2. Open c:\windows\SoftwareDistribution\Download
3. Delete everything in that folder. These are just the installers for the updates you’ve already installed, so it won’t hurt anything.
4. Open Windows Update and pick the update that you’ve been having trouble with. It will be re-downloaded and, with any luck, it will install without any issues.
5. Start the Automatic Updates service.

Hope this helps someone. Or at the very least it will help me when I run into the issue again in a few months.