Unplug it for 30 seconds. Plug it back in. That should "reset" the printer. You may also want to make sure that your printer and computer are on the same network (I find this happens a lot with my laptop, especially in connecting between my regular Xfinity connection and the Public Xfinity connection). If your computer and printer are on different wireless networks, it will always show as "offline". If it will not connect after these two steps, you will probably need to contact HP. Hope that helps!