Holy cow, I wrote a book!
Windows XP shipped with new icons for many common items in the
shell, and Windows Vista will have even more and newer icons.
One of the things the designers have to be careful about with
drawing these icons is to make sure they don't actually look like
Let me clarify.
The folder icon, for example, is not based on any actual physical
folder you can buy in the store.
If it were a rendition of an actual folder,
Windows would become vulnerable to a copyright infringement
charge from the manufacturers of that folder.
Instead, the manila folder icon is just something the designers
made up from their fertile imagination.
As another example, Windows XP came with new icons for
the drives in your My Computer folder.
One company complained that the icon for removable mass storage
devices too closely resembled the drive manufactured by their
The designers had to go back and draft a new icon that looked
even less like any actual drives out on the market, yet which
users would still recognize as a removal mass storage device.
That's why icons can't look like anything.