I just spent way too long trying to figure out why an hp wifi printer keeps going offline (for win7 laptop) whenever the printer is turned off and back on. My biggest obstacle was that I didn't realize til late that the router administration webpage for the XFinity router (Arris brand) was displaying incorrect information. E.g. many times it did not show the printer as attached, but I could ping the printer IP from Win7. Conversely, the webpage displayed the printer as attached when the printer was unplugged / off. Other times the webpage displayed the wrong IP for the printer. When I "factory reset" the router, I seemed to get accurate info from the router admin webpage, but after a while, the bad info issue returned.
Is this a BROWSER issue? (Due to my browser showing me old copies of the webpage?) Or is it due to the ROUTER?