How to Reinstall Failed Updates
Microsoft periodically releases updates to its Windows Vista and Windows 7 operating systems. These revisions are delivered to the system over an Internet connection through a built-in utility called Windows Update. Although downloaded updates generally install without issue, software conflicts or other system issues may cause the installation process to fail. To work around these problems, use Windows' System Restore utility to roll your system back to a previously saved configuration and then run Windows Update again. Once you understand the required steps, performing these tasks takes only minutes.
Restore Windows to an Earlier Configuration
Close all open programs.
Click the Windows "Start" button, and select the "Start Menu" search box.
Type "rstrui" (without quotation marks) in the resulting field, press the "Enter" key and then confirm your choice if prompted by Windows. The System Restore utility appears on your screen, generally in less than 1 minute.
Select "Choose a Different Restore Point" and click "Next."
Look to the "Date and Time" column on the left side of the window. Select a restore point that was generated before you attempted to install the most recent Windows Update package, and then click "Next."
Click "Finish." Windows will automatically shut down and then restart itself, loading your selected restore point in the process.
Run Windows Update
Click the Windows "Start" button and select the "Start Menu" search box.
Type "update" (without quotation marks) in the Start Menu search box and then click the "Windows Update" item that appears in the list of results.
Click the "Check for Updates" item on the left side of the resulting window. Windows Update generally returns the most current list of available updates in less than 1 minute.
Click the "Install Updates" button and confirm your choice if prompted by Windows. Depending on the type of updates you are attempting to install, you may need to confirm your choice one or more additional times.