Could you unplug the Kobo and then try a reset on it? See
How do I reset my Kobo Touch for instructions on that.
After it's reset try plugging it back into the laptop.
Any possibility the battery might be totally flat? Since you mention a Blackberry I think those do come with a wall-charger that you should be able to connect to the Kobo to charge it. If so... leave it charging on that for a few hours and then try connecting to the PC again.