I have a custom Feature, with Site Collection scope, that won't go away even after I delete the Web Application, the Content Database, the IIS Web Site.
I have uninstalled the Solution that contained the feature, and
stsadm -o enumsolutions shows nothing. I'm not sure whether any of the SharePoint PowerShell commandlets could enumerate solutions as well.
When I create a new Web Application and a new Site Collection, the custom Feature is in the list of Site Collection Features for the new Site Collection.
I've tried rebooting and resetting IIS.
How can I find what's causing this? Could it be a farm-scoped feature that remains? If so, how do I find it? And how do I remove it?