Where event receiver is deployed?

Event receivers are usually deployed via a feature. A feature can be scoped to farm, web application, Site collection or web.

The scope of a feature has nothing to do with the way SharePoint deploys a solution that installs that feature.

A solution is deployed either globally or to a web application. SharePoint decides how to deploy a solution according to the solution manifest :

- If in the solution manifest, the assembly's attribute DeployementTarget="GlobalAssemblyCache", SharePoint will not ask you for the web application.

- If the attribute DeployementTarget="WebApplication", SharePoint will ask you for the web application to which the solution will be deployed.

- If the attribute DeployementTarget="GlobalAssemblyCache" and SafeControls are needed for the assembly, especially for web parts, SharePoint will ask for the we application, because the safe controls are added to the web.config of the web application.

To see the solution manifest, change the extension of your solution file from .wsp to .cab e.g. Mysolution.wsp to Mysolution.cab. Then use windows explorer to open the file and extract the file Manifest.xml.

Hope this helps,