You do not have access to these files from your current OS. The previous poster noting this as the issue is correct, but it is not necessary to use a third party app to do so.
First, certain files cannot be deleted even if you do take ownership of them as they are in use by the current OS, ie, boot manager.
Properly apply 'administators' as the owners of the folders and all subfolders (not the root), boot to safe mode, and then you can delete them. Make sure you are seeing all hidden files and folders on that drive.
Use care not to delete the wrong ones.
If on re-boot (after safe mode), your system does not boot, insert your Windows 7 Disk and run boot repair.