For those who want to block unwanted SharePoint installation within their Corporate Network, create a new software restriction policy using the following registry
HKLM\Software\Policies\Microsoft\Shared Tools\Web Server Extensions\14.0\ SharePoint\
Another solution is to deploy, using GPO, the registry key with the following information:
Path: HKLM\Software\Policies\Microsoft\Shared Tools\Web Server Extensions\14.0\ SharePoint\
Key type:DWORD
Key name: DisableInstall
Value: 00000001 (to block installation)
Don’t forget to document this security settings, and to manage correctly your server to be able to deploy SharePoint on specified servers 