This is from the Windows Team Blog:
“Starting February 24, we will be releasing up to 5 test updates to PCs running the Windows 7 Beta (Build 7000) via Windows Update. These updates allow us to test and verify our ability to deliver and manage the updating of Windows 7. We typically verify servicing scenarios during a beta.
Windows 7 Beta users will be notified that new updates are available beginning February 24 through Windows Update. Even if the user has Windows Update configured for automatic update â€“ these test updates will not install automatically. Users will need to manually install the test updates through Windows Update.
These updates do not deliver new features or bug fixes. The test updates simply replace system files with the same version of the file currently on the system.”
I’ve been running the Windows 7 Beta next to Linux Mint for a couple of weeks now, without any problems.