Which is the best option for you?
Most people either find the automatic update/install option the most convenient, or simply don’t even think about it. If you are in any doubt, this is the safest and simplest choice.
You may wish to select the middle two options if you find the automatic downloads too much of a hassle, for example if they clog up your internet connection or if they make your computer take too long to shut down (which can be a pain if you are using a machine at work and need to get out of the office quickly!)
Sometimes a particular update causes problems with third party-software. For example, an update to the Windows Media Player caused problems with an independent program used for streaming video to a TV set. In cases like this, you might want to take more control of which downloads to install and which to skip.
If you keep up to date with technology websites, you may decide it’s worth waiting a couple of days before installing new updates to find out if there are any compatibility problems. For example, a recent update to Windows caused users of the popular ZoneAlarm firewall to lose internet access. The big drawback to this is that the first couple of days after a security update comes out is the time you are most vulnerable to attack. That’s because hackers can look at the technical information behind the update and figure out more about the loophole it is intended to close.
If you want complete control of your computer, turning automatic updates off completely could be the best option. But this is really only viable for people who are very confident and are prepared to keep up-to-date and check the Windows Update site regularly.