Hello Pik Lee,
_vti_cnf are FrontPage server extensions which allow sites to be synchronised with FrontPage. You can delete them if you have no intention of using FrontPage. Sitefinity installation does not come with these folders.
All the best,
the Telerik team
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Public Issue Tracking
system and vote to affect the priority of the items.