Please consider and remember when the printer or the scanner did work properly. Also give a moment to note what has happened recently, before the onset of the current problem. The record will help to continue to narrow down the likely cause or causes and most quickly arrive at the solution for this problem, for these two problems.
Perhaps you have a hardware problem with a hub that connects the printer device and the scanner device to your PC, but lets look at and try some very basic things to try to fix the problem before even pursuing any hardware repair or hardware replacement.
First start with basics. If you have recently added camera software and a USB camera or a Firewire IEEE 1394 cabled camera, remove the camera for this trouble shooting activity, to see and try to get the printer to work again. Leave the scanner disconnected too.
Start the computer. Check to see if the device is found and is identified correctly. For the printer, see if it appears in your list of printers. On a PC, see in the Start Menu, the item Printers, or Printers and Faxes. Move your mouse pointer over it and see what message may appear. Right click on the printer and select properties. See the condition of the printer. After you have right mouse clicked with your ring finger, click on properties. Let's start by getting your printer to work. Maybe locate your Canon software driver installation CD, or go to www.canonusa.com/support
for the driver and download it, choosing to Save it to your desktop or into C:Temp or C:Downloaded Printer Driver - Canon (if you do not know how to select the destination folder, do not select Save, simply select Install. The advantage of save before doing install is to have the driver available to make a driver CD for any other trouble shooting or computer reload activity you may want to or may need to do, to get the printer working sometime again in the future.) The ways to fix the printer problem include first, simply disconnecting the printer, then reconnecting it to the PC, and checking to be sure the printer is powered on, is online, not offline, and is actually well connected properly to the computer. The next thing to try will either be to delete the printer from the Printers in the computer and then to readd the printer. The driver will be needed so it is very helpful to have the driver installation CD or the downloaded driver - it is necessary in many situations, but some printers have drivers included in the Windows 2000 or Windows XP Home or Windows XP Professional or Microsoft Vista operating system. Best to have the newest correct driver from the manufacturer website before deleting your printer, and then proceed to delete and readd the printer. Your printer may have a flashing indicator light, a blinking that you can match up to a solution in the printer user manual or printer operator manual or the printer manufacturer's printer troubleshooting and support website. The small display screen may indicate the printer is offline because of a paper jam or because the ink supply has run out. Resolve any problem with the printer. See if this fixes the printer problem. Then proceed to add the scanner, or disconnect and reconnect the scanner, or download the driver or locate the manufacturer supplied scanner software installation CD and drivers that are needed for your computer to run the scanner. Sometimes you will find that you can set up the printer and the scanner to work directly to the printer, and then after working properly, disconnect the cable and connect the printer USB cable to the USB hub. Do the same steps to get your scanner working with it connected directly to the computer, then try to connect it to the USB hub and shut down the computer and restart the computer, and see if all is resolved by these steps.