Not sure..I am sure it involves holding the power and some other button during bootup but I do not know the sequence and it is not (easily) located on the canon website.
This, however, may help you on your way to whatever it is you're trying to do with the Canon PIXMA IP1600:
http://www.ubuntu.sumy.ua/2010/06/ca...-1004-lts.html
Yes, Yes I KNOW it is in russian, but the actual streps are in "linux"
Good luck.