I am assuming you scanned the network and found the IP address that is assigned to the network card of the printer, but when you wanted the OS to determine the driver the driver was not found. If you already have the driver installed when you locally attached the device just add the printer selecting the Standard TCP/IP port that was created earlier and select the driver from the list on the Manufatcure/ Model driver page.
You can also run 'printui /ip' from command line and select the driver from the list of preinstalled drivers.
Most likely the hardwareID from the network interface does not match up with the same as that over USB. You could look in the Windowsinfsetupapi.dev.log but I find the log too full of other device installs that finding the printer is a needle in a haystack unless you know precisely what to look for.
PS the print driver is not included with the Windows 7 operating system so you need to give Yaaser a break. Did HP give you a driver name to use? HP did include a driver for this model in Windows Vista but you will need to be connected to the internet in order to download the driver from Windows Update. Alan Morris Windows Printing Team Search the Microsoft Knowledge Base here: http://support.microsoft.com/search/Default.aspx?adv=1