How do i shred deleted user account

afaik, the documents and application settings are stored under C:\Documents and Settings\<username>

if you shred delete that folder the files won't be able to recover.

as far as whether there's any other entries, there's definitely a record of a user account in the registry, but it should be deleted once the user is no longer present. But I'd recommend to run a registry clean up after account deletion to make sure.

if there's any other windows directories that have account relevant information, I'm not aware of them