Just some examples that some sites "claim"
they can see
Your C Drive:-
Program Files:-
The contents of Windows:-
Users on the Computer:- (Win XP)
Programs in your start menu:-
For users on non-updated PCs the following is also available:-
Recent Websites:-
Recently viewed Files:-
Files in your "My documents" folder:-
Your windows desktop:-
Your PC:-
Your Network Connections:-
Even your recycle bin:-
In fact just about any Folder on your PC is accessable including
Temp Internet Files, My Pictures, Favorites, Control Panel, Application Data
and Windows System Files.