Instalar SharePoint 2010 no es tarea facil...

Hay algunos inconvenientes que se presentan en la instalacion de SharePoint 2010, Microsoft nos alerta de esto y nos deja una guia de configuracion donde se nos aclaran algunas cosas, como por ejemplo de que al momento de la libracion de la version RTM, no podremos migrar nuestros trabajos en BETA a final...

Since SharePoint 2010 has been made available for MSDN/TechNet subscriber public now, here’re some steps you would like to follow to get a successful installation. But keep in mind: This beta is not supported and you CANNOT upgrade the installation to RTM when it’s released. This Beta should only be used for evaluation purpose.

http://blogs.msdn.com/opal/archive/2009/11/16/installation-notice-for-sharepoint-2010-public-beta.aspx

Pero bien, en el lin pueden ver los detalles de la instalacion, y tambien algunas consideraciones que surgen en la instalacion de SharePoint sobre Windows 7 y sobre Windows 2008R2

Cuentas de servicio:
To get all benefits of SPS2010 you require domain service accounts as spotted
You can use local accounts by following this blog Single Server Complete Install of SharePoint 2010 using local accounts

Server 2008
Follow Jie Lie's post above to install the beta on Server 2008. Pre-requisites can be downloaded using the Installer (if you have an internet connection) otherwise please refer to this page for a detailed list of prerequisites with download links.

Server 2008 R2
PowerShell v2.0 is already installed with Windows Server 2008 R2 and the CTP3 recommended by Jie Li will not install.
The installer will run fine on Windows Server 2008 R2. What will not work are a) all the service apps and b) the user code service (aka sandbox solutions).
There is a hotfix (KB971831) that's currently available here . Install this hotfix *before* you run the SharePoint installer and reboot. Service apps will work correctly after you do this.
KB976462 is available under MS Connect accounts. Go and enjoy!

Windows 7
MSDN has a great article on how to get the install to run on Windows 7
SharePoint Solutions also have a post on this
External References
Installing SharePoint Server 2010 beta 2 on a single machine

Mas informacion sobre el error : http://social.msdn.microsoft.com/Forums/en-US/sharepoint2010general/thread/041ddc78-8d18-4753-b7be-8d8113e26e62

Mas informacion la pueden encontrar en el SharePoint Developers Center http://social.msdn.microsoft.com/Forums/en-US/sharepoint2010general/threads donde estan categorizados todos los inconvenientes de esta version.

No olvidarse de que se trata de la Primer Beta Publica del producto y que la finalidad de ser BETA es la de juntar feedback sobre errores, inconvenientes en instalacion y uso y mucho mas...