Does this look familiar ?
Like ... exactly the content of your C: drive ?
And see what happens if you click on one of these files or folders ...
So now I know who you are and where you live ... be afraid, be very afraid :-)
The paragraph that says what operating system and web browser and screen resolution you are using, was created with information that was collected as you opened this page. So it is possible to have a web page collect information about the computer you use to visit that page. They can display this information in the page, or send it to whoever owns that page. And worse. They may even execute a program (such as a 'virus') as soon as you get to that page (demo).
Scripts are easy : cut and paste. These free scripts were provided by JavaScriptKit : Cut and Paste JavaScript
However, the picture of your hard disc is, in this case, just an innocent html tag, that displays the content of your C: drive in a frame, almost like displaying a picture. But still ... scary, isn't it ?
However, with Visual Basic you can really access the hard drives, folders and files in a computer, and visual basic can be used in web pages easily.