This is common with all QC versions.

Sometimes, a project will not ''delete'' for various reasons.

When you perform a ''delete'' from Site Administrator, what it does is 3 things:

1) Deletes the Repository folder corresponding to the project,

2) Deletes the database/Schema relating to the project, and

3) Deletes the RECORD corresponding to the project from the ''PROJECTS'' table in the qcsiteadmin_db Schema/Database.

You can do all 3 steps MANUALLY if you want.

Of course, BE VERY CAREFUL that you delete the correct folder/record/Schema.

It might take a cycle of the QC/ALM Service to see that the project is out of the list.