Microsoft is going to release 5 test updates for Windows 7 Beta Build 7000 on
Tuesday, 24 February 2009.
These updates will help Microsoft in verifying its ability to deliver and manage the updating of Windows 7 in certain scenarios in the future.
These
updates will not install automatically so you'll need to install them manually from "Windows Update" applet in Control Panel.
These updates are optional and you can hide them if you don't want to install them.
You can read more information about these updates at following link:
Source