Networked scanning

I have a HP All-in-One printer connected to a laptop.
The laptop and a desktop computer are connected to a router.

I can print/scan from/to the laptop without any problem.
I can print from my desktop through the router without any problem.

Is there a way to scan a document to the desktop computer via the router?

One would thing if it works for printing it should work for scanning or hasn't Microsoft gotten around to programming for that functionality yet?

Thanks for your attention and have a great day... Gandalf

EDIT: the laptop is running Vista and the desktop is running Windows 7.