To delete a team project collection completely, You need to take 3 Actions
- Delete collection
- Delete Database
- Delete Sharepoint Site
- Open Team Foundation administration console.
- Go to Application Tier, and then choose Team Project Collections.
- In the list of collections, highlight the name of the collection that you want to delete.
- On the General tab, choose Detach Team Project Collection.
- The Detach Team Project Collection Wizard opens.
- Follow the wizard.
- When all the readiness checks have completed successfully, choose Detach. When all processes have completed, Choose Close.
- The team project collection no longer appears in the list of collections in the administration console.
- Open SQL Server Management Studio, connect to the instance of the SQL Server Database Engine that hosts the collection database, and expand the instance.
- Highlight the name of the collection database (by default, TFS_CollectionName), and then delete the database.
Delete Sharepoint Site
- Open SharePoint Central Administration, and delete the site collection linked to deleted collection