I strongly recommend that you set Windows Automatic Update to “Notify but don’t download.” For detailed reasons and an explanation of the options involved, see my Windows Secrets article, New Years resolution: banish automatic updates.
Here’s how to set Windows to Notify but don’t Download:
Windows 8: While looking at the old-fashioned Windows desktop, hold down the Windows key and press X, then choose Control Panel. Then follow the instructions for Windows 7.
Windows 7 and Vista: Using an administrator-level account, click Start, Control Panel, and then System and Security. Under Windows Update, click the Turn automatic updating on or off link. In the drop-down box, select Check for updates but let me choose whether to download and install them, then click OK.
Windows XP: Click Start, Control Panel, and then Security Center. Click the down-arrow to the right of Automatic Updates. Click the icon marked System and then the Automatic Updates tab. Choose Notify me but don’t automatically download or install them, then click OK.