If you go to "Control Panel\Hardware and Sound\Devices and Printers" in Windows 7 (and i assume vista) you will see some nice pretty pictures of printers.
See image below
Is it possible to get access to these images through .net?
For example to display them on a windows form?
They'll be Microsoft copyrighted...
If you still really want to grab them there will be some DLL kicking around with them in. There's some in c:\windows\system32\shell32.dll although you'll need to check to see if these are the ones you want. You should then be able to extract the icons with an standard icon editor (e.g. IcoFx) straight from the DLL.
You don't need to extract them from Vista's DLLs (also it's possible). take a look at VitaIcons, you can download completed vista icon set there. but if you need to use Vista's original icons, extract them by an icon editor program from kernal files and dlls of vista.
some icon editors:
http://www.rw-designer.com/vista-icon-editor
http://www.freedownloadmanager.org/downloads/vista_icon_editor_software/