Still running Windows 7 Release Candidate? make plans to move to a RTM ASAP
On June 1st, 2010, a non-genuine experience is triggered where your wallpaper is removed and “This copy of Windows is not genuine” will be displayed in the lower right corner above the taskbar. This means your PC will no longer be able to obtain optional updates or downloads that require genuine Windows validation.
To avoid any data loss, I suggest making plans to move to a released version of Windows 7 before the automatic shutdowns start. During these shutdowns, your work will not be saved.
Remember, pre-release versions of Windows are unsupported. For more information on the expiration of the Windows 7 RC, see this KB article.
If you would like to keep on testing make sure you download the Windows 7 Enterprise 90-day trial.