Install Windows updates
Applies to all editions of Windows Vista.
To have Windows install important updates as they become available, turn on automatic updating. Important updates provide significant benefits, such as improved security and reliability. You can also set Windows to automatically install recommended updates, which can address non-critical problems and help enhance your computing experience. Optional updates are not downloaded or installed automatically. To learn more about the types of updates that Microsoft publishes, see this
Knowledge Base article on the Microsoft Help and Support website.
If you do not turn on automatic updating, make sure that you check for updates regularly. For more information, see
Turn automatic updating on or off and
Change how Windows installs or notifies you about updates.
To check for Windows updates
1. Open Windows Update by clicking the
Start button

, clicking
All Programs, and then clicking
Windows Update.
2. In the left pane, click
Check for updates, and then wait while Windows looks for the latest updates for your computer.
3. If any updates are found, click
Install updates.

, If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
To install drivers and other optional updates
To install optional updates, you need to review and then select them from the list of updates that Windows finds for your computer. Optional updates are not installed automatically.
1. Open Windows Update by clicking the
Start button

, clicking
All Programs, and then clicking
Windows Update.
2. In the left pane, click
Check for updates, and then wait while Windows looks for the latest updates for your computer.
3. If any updates are found, click
View available updates.
4. Select the optional updates that you want, and then click
Install.

, If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
Source: Microsoft