Had same problem on the mac OSX. Went to printer web address which access printer over the network. Under "setup" look at far right side of screen and click on "networking" button. Another screen pops up with all the network setting. Selected IP Configuration Method "manual" and typed in the last IP address I had on the printer (should be same one you have always had). Basically, once you have connected to printer copy down the info and go in and choose manual and plug in same info. I also had to turn off the check box at bottom of the page "Send DHCP requests if IP address is Auto IP..."
Again this is all on my mac so don't know if the web info even looks/is the same.
HP support gave me most of this info and it worked for awhile, I figured out the manual address thing. Call HP, they are pretty easy to get ahold of: 1-800-474-6836
Good luck.