I found this in a few different places around the 'net - hopefully it's helpful:
How to Have Windows Remind You About Pending Updates
- Click Remind Me Later in the Automatic Updates dialog box before you download or install the update.
- In the Reminder dialog box, you can specify the amount of time Windows should wait before reminding you.
- If the reminder is for downloading, Windows reminds you only when you are connected to the Internet.
- If the reminder is for installing, Windows reminds you according to the schedule that you specify.