You have installed a USB or network printer to your PC, turned it on and inserted the paper and you have chosen the Print command in windows 7. Sometimes it is unable to print a document from computer because the printer is offline, which will prevent all future jobs from printing. Print command would make an instant error on the printer itself and therefore take it offline. When this happens, it could prevent all of your expected paperwork from allowing you to print using your printer. To resolve this issue, you will need to change your printer settings from offline to online

1. Open the Start menu and click on the Printers and Faxes icon
2. Then it will show all printer currently installed in your computer
3. Double-click on the icon of the printer you want to change to online
4. Then another window will appear informing you of all the current print jobs
5. You can proceed to Printer in the menu bar and uncheck Use Printer Offline
6. This will instantly modify the printer from offline to online setting

If you are using HP printer, continues to go offline, another issue such as a virus or hardware or software problem. If you are using Mac then click on the Resume printer to make it online from offline