I found this in a few different places around the 'net - hopefully it's helpful:
How to Update Your Files Manually by Using Windows Update
If you choose not to use automatic updating, you can still install specific updates from the Windows Update Web site. Windows Update is a catalog of items such as drivers, security fixes, critical updates, the latest Help files, and Internet products that you can download to keep your computer up-to-date.
- Click Windows Update in Help and Support Center.
- On the Windows Update home page, click Scan for updates.
- Click Yes when you are prompted to install any required software or device drivers.