Hello,
First thing is to go to this page:
HP OfficeJet 7310 Support
(Bookmark this page for future use.)
Select Software & Driver Downloads. Then select your operating system. (Vista) A list of availble software will be given. Click on the name of the software to download.
When the download window comes up, select Save and direct it to save to your desktop. When the download is complete, close the window and any other open programs.
Prepare your printer: power ON, ink IN, paper IN, telephone line IN (if used).
DO NOT CONNECT YOUR USB CABLE.
Run (double-click) the file on your desktop that you downloaded. When promted by the software connect the USB cable and follow any other instructions. That should get you going.
Note: There is also a link on the download page to order a CD if so desired. You could also burn one with that desktop file on it.
Thanks for using Fixya.