Você não deve atualizar uma versão RC (release candidate) para uma versão RTM (release to market), portanto o instalador do Windows 7 RTM não permitirá a você sem algum hackery de um arquivo no disco do Windows 7 Professional.
On February 15, customers will begin receiving automatically generated notifications, warning them that their operating systems will expire and that they need to back up their data.
Beginning March 1, users’ systems will reboot every two hours and work will not be saved.
Mais especificamente, a Microsoft quebra a expiração em duas categorias - a "Bomba-relógio" e depois "Expiração da licença":
User starts seeing Notifications 14 days before time bomb date. Notifications indicate that system will expire and that data needs to be backed up.
After the Time bomb date system blue screens or reboots every 2hrs, depending on the System failure settings in Start up and recovery options. Our activation wizards are displayed frequently indicating that the system has expired.
Approximately 3 months after the time bomb date, the licenses in the system expires. When the licenses expire, the system gets into Notification state. The notifications are more intrusive occurs during logon, periodically in Action Center, accessing system components such as control panel and finally the desktop background turns black with a non-genuine watermark. The trusted time is used for this check, so it is difficult to game around this timer.
A Microsoft tem um PowerPoint sobre a "Experiência do usuário de expiração pré-lançamento" que inclui capturas de tela dos vários diálogos .
Seus planos de reformatar e instalar o Windows 7 RTM são o caminho certo a seguir.