1. Check with your System Administrator to ensure that you have the correct permissions for the files or folder wanting to be deleted.

2. Ensure that the files or folder being attempted to delete are not currently in use or open by another user or application.

3. Try to delete the files or folder using a different user account with administrative privileges.

4. Boot into Safe Mode and then try to delete the files or folder.

5. Make sure that the files or folders being deleted are located on a physical drive and not a mapped network drive.

6. If it is a folder being deleted, make sure it is empty before attempting to delete it.

7. Use a third-party application (i.e. Unlocker) to forcibly delete the files or folder.