How to find out the type of SharePoint installation
SharePoint 2010 can be installed as a Farm installation or as Standalone one. Standalone installations means that all the components are on the same machine (SharePoint, SharePoint services and built-in database) and this type of installation is not extensible.
You can find out which type of SharePoint installation was used via Registry edidor (regedit). You should open node:
- For SharePoint 2013
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Shared Tools\Web Server Extensions\15.0\WSS\
- For SharePoint 2010
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Shared Tools\WebServer Extensions\14.0\WSS\
- For SharePoint 2007
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Shared Tools\Web Server Extensions\12.0\WSS\
And see "ServerRole" value. If its value is equivalent to "Application" or "WFE", then you have full farm type. If its value is equivalent to "SINGLESERVER", then you have a standalone type.
You should remember, that Microsoft does not support upgrading from the single server installation type to a full farm installation type. It's good only in test environments or on developers machines.