You may also try these:
1. Open the Start menu and click on the "Printers and Faxes" icon. This will open a window with a list of the printers currently set up on your computer.
2. Double-click on the icon of the printer you want to change to online. A pop-up window detailing all current print jobs will open.
3. Go to "Printer" in the menu bar of the pop-up window and uncheck "Use Printer Offline." This action will change the printer from offline to online.