Updating your computer by using automatic updating, or by manually checking for updates, is the preferred way to get updates. Sometimes, however, computer, security software, or connection problems can prevent scanning or installation of updates. When this happens, here are a few things you can try:
If you have automatic updates turned on but some updates fail, try scanning for updates manually. This can sometimes fix the problem.
Be sure your computer is virus-free and malware-free. Run your antivirus and antispyware scanners before running Windows Update.
Close all your programs, and restart your computer. It is possible that another program might be preventing Windows Update from working.
Check your Internet connection. Be sure you can visit other websites before running Windows Update. Connection problems can trigger errors that can appear to be caused by other factors.
If you know the update you need, such as a service pack or security update, you can search the Microsoft website. Most updates also have a knowledge base article (KB) that explains the update, and most updates provide instructions on how to download and install manually.