Operation Name: Installfeature
Used to install a feature. Farm-scoped features are also automatically activated during this stage. Other features might still need to be activated.
 
Syntax:
stsadm -o installfeature
   -filename <relative>
   -name <feature folder>
   [-force]

Parameters:
Parameter Value Required? Description
filename A valid file path, such as "MyFeature\Feature.xml" Yes

Path to feature must be a relative path to the 12\Template\Features directory.

name Name of the feature folder, such as “MyFeature” Yes Name of the feature folder located in the 12\Template\Features directory
force <none> No Forces an installation of a feature that is already installed
Reference: http://technet.microsoft.com/en-us/library/cc263123.aspx 


Operation name: Uninstallfeature
Removes the specified feature definition from the collection of feature definitions in the farm. 

Syntax:
stsadm -o uninstallfeature
   -filename <file name>
   -name <feature folder>
   -id <feature ID>
   [-force]

Parameters:
Parameter Value Required? Description
filename A valid file path, such as "MyFeature\Feature.xml" Yes

Path to feature must be a relative path to the 12\Template\Features directory.

name Name of the feature directory, such as “MyFeature” Yes Name of the feature folder located in the 12\Template\Features folder
id A valid GUID, such as “00BFEA71-EC85-4903-972D-EBE475780106” Yes GUID that identifies the feature definition to remove
force <none> No Forces the feature to be uninstalled.
Reference: http://technet.microsoft.com/en-us/library/cc262976.aspx 


Operation name: Scanforfeatures
Scans for new features in the file system, and if new features are present, installs them. 

Syntax:
stsadm -o scanforfeatures
   [-solutionid] <GUID>
   [-displayonly]

Parameters:
Parameter Value Required? Description
solutionid A valid GUID No GUID that defines the solution
displayonly <none> No Scans only for new feature definitions, but does not add them to the collection.
Reference: http://technet.microsoft.com/en-us/library/cc263234.aspx


Operation name: Activatefeature
Activates a feature in the feature collection. You must first determine the scope of the feature. If the scope is Web-based or is a site collection scope, the url parameter is required. However, if the scope is farm-based, the url parameter is not required. 

Syntax:
stsadm -o activatefeature
   -filename <relative path>
   -name <feature folder>
   -id <feature ID>
   [-url] <URL name>
   [-force]

Parameters:
Parameter Value Required? Description
filename A valid file path, such as "MyFeature\Feature.xml" Yes

Path to feature must be a relative path to the 12\Template\Features directory.

name

Name of the feature folder, such as “MyFeature”

Yes Name of the feature folder located in the 12\Template\Features directory
id A valid GUID Yes GUID that identifies the feature to activate
url A valid URL Yes URL of the Web application, site collection, or Web site to which the feature is being activated
force <none> No Activates a feature. This causes any custom code associated with the feature to rerun.
Reference: http://technet.microsoft.com/en-us/library/cc262692.aspx


Operation name: Deactivatefeature
Deactivates a feature in the feature collection. 

Syntax:
stsadm -o deactivatefeature
   -filename
   -name <feature folder>
   -id <feature ID>
   [-url] <URL name>
   [-force]

Parameters:
Parameter Value Required? Description
filename A valid file path, such as "MyFeature\Feature.xml" Yes

Path to feature must be a relative path to the 12\Template\Features directory.

name Name of the feature directory, such as “MyFeature” Yes Name of the feature to deactivate
id A valid GUID Yes GUID that identifies the feature definition to remove
url A valid URL Yes URL of the site collection or Web site to which the feature is being deactivated
force <none> No Specifies that a deactivation of the feature will be forced.

Reference: http://technet.microsoft.com/en-us/library/cc262680.aspx