Printer/USB Problem…. Please Help!

I have Windows XP.
I also have a Canon multi-function printer.
There’s two computers, one in the living room – one in my bedroom…
Recently switched from DSL to cable.
Have a router.

My printer won’t work!
When I plug it in to the USB port
(also when I plug my flash drive in!),
the computer shuts down!

What’s wrong?

I’ve ran virus scan.
Tried up-dating drivers.

Please help!
Thanks.