Windows Vista hides important files and folders from view to keep users from deleting or otherwise modifying files they shouldn't, but a simple checkbox can change that behavior.
To show hidden files, just click on the Organize button in any folder, and then select "Folder and Search Options" from the menu.
Click the View tab, and then you should select "Show hidden files and folders" in the list.
Just select that, and click OK.
If you are trying to get into the Windows directories, you might want to also remove the checkbox from "Hide protected operating system files" as well.