After uninstalling K2 blackpearl and performing the manual steps, reboot the machine. Then, to ensure the environment does not have any K2-related components, use the following checklist:

1. No K2 Databases are present on the SQL Server
2. The K2 blackpearl menu items are not present under Start > Programs
3. No K2 components are present in Add/Remove programs (Start > Control Panel > Add/Remove Programs)
4. No SourceCode nodes are present in the machine.config file
5. No SourceCode assemblies are in the GAC (C:\Windows\Assembly)
6. No K2 blackpearl folder is located under Program Files
7. No K2 For SharePoint tab in the SharePoint 3.0 Central Administration Site
8. No K2WorklistWebpart.wsp located in the SharePoint 3.0 Central Administration Site
9. No issues opening the SQL Server Reporting Services home page