Deleting quarantine files

What file extension do Norton AV quarantine files have?  I have to delete some 51 GB of quarantine files of trojans caused by a virus.  I have been unable to delete them through the AV program itself because they were moved to windows.old when I upgraded to Windows 7.  I am hoping to be able to delete them using the delete key if only I can fine them.

 

Thank you for your help.

 

Peter