My new laptop with Windows 7 won't recognize my wacom pen tablet?

I've been using an old desktop that has windows XP, but I just got a new laptop, and the tablet worked when I downloaded Windows 7 drivers, but then the next time I plugged it in I had to install it again. And now when I try to install the tablet again, it says there isn't a recognizable tablet plugged in (my tablet lights up like usal, but it's flashing)