Have you ever gotten the error from your Canon printer, “Another computer is using the printer” and had no idea how to resolve it? Here’s the solution (and then I’ll bitch, moan, and complain after, that way you can get right to printing instead of wasting time scrolling down half the page trying to find the answer. You’re welcome.):
STEP 1: Power off your printer.
Make sure the green light stops flashing! The printer needs to be completely OFF and powered down. so press the power button once–and wait. Give it a good 30 seconds.
STEP 2: Power on your printer.
Just press the power button once. Your printer should power on and go through it’s warming up sequence, humming, purring, and bzzzt!ing. At this point, whatever has been waiting to be printed SHOULD begin to print. This is how I’ve resolved this issue every time it’s come up with my printer.
I hope the above steps help you solve the issue “Another Computer Is Using This Printer.” If not, I recommend the following.
SHUT IT ALL DOWN.
1: Power Off your Printer.
2: Power Off/Unplug your WiFI Router.
3. Power On/Replug your WiFi Router.
4: Power on your Printer.
LAST RESORT
Finally, if all that fails, I recommend removing your printer from your computer then re-adding it. This is another process that many websites have laid out.